The Monstrous Vortec 8100 496 8.1L Big Block Engine of the 2000's 

Thank you for making this enjoyable video. Bought a used 2004 2500HD CC long bed LT with the 8.1L in 2005 with 19,500 miles. Was like new and paid $22,500 for it. The truck just turned 300k miles and has proven to be one of the top purchases I’ve made. Repairs: 1 coil pack, 4 sets of plugs, TPS replacement, 1 alternator, 1 master cylinder, all new brake lines, driveshaft carrier bearing, Windshield washer pump, new AC compressor and I’ve had various electrical issues (none severe). Normal brake maintenance etc.. Have friends that have purchased 4 or more trucks in the time I’ve owned the 2500HD 8.1L and have not once felt the need to shop for anything else. I believe, in several ways, buying a new truck would be a downgrade.

I have the 2001, 270,000 and it is still as strong as it ever was , Love the set up of the Trans and motor , Headers and a Big K_N Filter ,

My 2004 Suburban tows a 12 ft cargo trailer all over the USA. 15 mpg on a good day. 250,000 miles, zero problems. If it had more gears it would get even better mileage.

I just bought my 1st 8.1 in a 2500 HD GMC Sierra and I fell in love on the test drive. Amazing how quiet it is and how smooth she rides. I’m the 3rd owner. Last guy had it for 3 years and an old man had it from the showroom floor before that and well cared for the whole truck.

I have two of these in my 2005 37’ Sea Ray. Great engines !

i can speak personally for this engine. i had one in a 2009 GMC c7500 and hauled GCWR of over 30k daily. had the 6speed manual trans and was geared very low. this engine spent most of its life at redline. i drove this truck with 75k on the clock for 3 years including a trip from St. Louis mo. to Fresno California. that's 4 days driving almost 12hr days and it topped out at 65 so it was pegged the entire time. the truck/engine never complained. stayed cool and kept running until we retired it at 80k and i was given a 2021 f750 with the 6.7, wish i still had that old gmc lol.

Love these engines. My 2002 burban 2500. Pulls like a champ starts every time. 10500lbs camper hooked up. Never misses a beat. 4l80e holds the power just just fine nice crisp shifts. 201000 and climbing. It’s a shame when something this reliable comes to an end.

A neighbor of mine just put one in an ASTRO van...! It was already LS swapped and not surprisingly because it's a GM product, it sold right in place of the LS with very minimal changes...! It's probably the fastest ASTRO van in Florida... Thanks for sharing... Keep up your awesomeness...!

I bought a 2001 2500HD new from the dealer with the 8.1. It is still my daily driver and my work horse @ 326.000 miles. I had to put a cam sensor in at 100,000 miles but no other issues. The truck itself has been beat to hell and back but keeps going. I have a couple of small leaks from oil lines and it burns a TINY bit of oil since day 1. I expect to have this truck and engine for at least another 250,000 miles. Yes, it has the Allison and I love that thing too.

Just dropped this beast in my 84 c10!!!

Got a 02 avalanche with 8.1 bought it with 96k now has 286k has not skipped a bit beat and still pulls like hell I love it.

@ 8:20 - 8:25 = (Lost Foam Casting ). I have this Vortec 8.1L in my 2000 National Surf Side . It's perfect for my application . It's the next best thing to a Diesel pusher . Thanks for the Great post .

Two comments about problems I’ve experienced with this engine… 1st glad you showed the back of the block. At about 90K miles I had the crank sensor fail and leave me in a Walmart parking lot. It’s not serviceable from under the hood, you have to reach up from underneath, around the bell housing and try to pull it out. In my 40+ years as a shade tree mechanic, I have never come this close to curling up and crying uncontrollably. I ended up having the truck towed to a local dealership for repair. At this point there were just wires coming out of the hole. When I asked the mechanic how he did it, he said “plenty of thread penetrating oil and a curved set of needle nose pliers”. A very frustrating and expensive learning experience. Second on the list, on my truck the exhaust pipe crosses behind the oil pan by just a few inches. Not a problem unless someone tries to use an impact wrench to remove/install the oil drain plug. The hole has been stripped for a number of years now and I can’t get any of the typical oil change businesses to change my oil because they don’t want to deal with a vehicle with a temporary plug in the pan. It’s a bit of an irritation at times. Other than these items, the engine is still running strong after 20+ years. Not too shabby

I have that engine in a 2003 motorhome, runs great and pulls hard.

Great video and yes very few people know about the 8100 Vortec. In my opinion and experience with these 8100's, they are the best ever made. I own a few 8100's and 7400's (all GMC duallies, Suburbans & Yukon XL) and my daily driver is a 2002 GMC Extended Cab dually 8.1/Allison with 4x4 on the floor and I'm close to 800k miles. The motor, transmission and axles have never been rebuilt or replaced. The only major part replaced has been the transfercase about 3 times but other than that, just regular maintance and minor parts it is needing that I have done myself. She is my baby and I take really good care of her always. Many people don't believe me about the mileage (especially diesel guys) and this truck is used to work hard and doesn't give up at all. I have always pulled with it all over Texas(my home) and a few more states and have done alot of traveling in it since the first day I bought her(15 years ago with 32k miles from the first owner like brand new😍) and she still pulls hard like a mean beast. I'm still searching for more to buy no matter the distance.lol Well I can go on and on but I really enjoyed your video and all the info is great and I'm looking forward to more videos and yes, I am a GM Big Block guy too👍Thats all I own since I drive🤠

I have an 2002 chevy crew cab dually 3500 with this motor. Bought it 2 yrs old. I still have it. Runs very well...no issues. It does consume some oil but nothing excessive or ridiculous. Plenty of power. I've pulled some heavy trailers and it's done well. It does use gas. 10 miles per gallon in city driving is the norm. Very dependable. Always starts and idles beautifully. Very quite and smooth.

I really think you missed your calling with this vid. Great explanation and detail, it's like a show aired on the history channel for the 8100!! I rarely turn that bell icon on for any channel but I will for this one!

I bought a class B motorhome based on the Express 3500. The 8.1 is very smooth, and it loves running at 75-80.

Awesome overview, great detail! I've got an 8.1 extended cab dually, and it pulls awesome. My only complaint is with the Torque Management system, which I intend to tune off shortly. The combo of this capable, simple engine in front of an Allison transmission makes it impossible to justify the cost of a new truck.

I picked up a 8100 6500 topkick with an LPG Version a few months back with 147k miles on it, so I am hope for some good luck with it on my food truck

I've had my 02 ccsb Chevy HD with the 8.1 for 4 years now. I still absolutely love it. It has a custom tune, set up for 89 octane and gets 11 mpg all around average. With 4:11 gears and 285 tires I can manage almost 12 mpg empty on the freeway under 75mph. I pull several trailers but it's biggest impact is my 20' steel frame cargo trailer. It's a foot overheight and bucks wind like crazy. The truck pulls it easy but I average 7 mpg with that no matter how much weight is in the trailer. As far as oil consumption. I've found old school conventional 10-30 is best. I use maybe a quart between oil change. I ran a synthetic and a blend a couple times to try but experienced poor results using as much as 3 quarts between changes to keep the ol girl full and happy. Thanks for your video.

I have this engine with the 5 speed Allison transmission in my 2004 Fleetwood class A motor home. It's a 32 footer and weighs in at around 21000 pounds. Fully loaded with everything including the kitchen sink and pulling a Toyota camery it gets almost 8 MPG and never misses a lick. Strong and dependable, and in my opinion the best non diesel engine ever put in a class A. The Ford Triton V10 is more popular in the older rv's like mine but you have to push them above 4500 rpm to make the power the 8.1 makes at 3200 rpm. I also like the idea of an all cast iron assembly instead of the aluminum heads on a cast iron block like the Ford. If you are thinking of buying an older class A and have a budget of around 25k the Vortec Workhorse chassis is the way to go.

+1 for the 8.1, I daily one of these in an 01 suburban. Lots of fun confusing and astonishing people when I tell them just how huge the engine is. To touch on the oil consumption issues as far as I've experienced/read, these engines will consume more oil when run on the factory recommended 5w30. I've found my engine using noticeably less oil after switching to 10w30 for the summer months and I'm currently testing 5w40 for the coming winter.

Bought my 2002 2500hd Silverado brand new. Now has 201,000 miles. Contiplating if I should do the timing chain. Right now truck is down for a whole new suspension. Almost done. Did a solid axle swap using 1979 Ford Dana 60 kingpin. 10 inch lift with 40's. As far as problems I have had: Crankshaft sensor went at around 38,000 miles. Common problem with these. Air intake manifold leak throwing p0101 code. I actually drove on it like this for 8yrs. CEL would only come on during hard acceleration. I had a exhaust manifold bolt break off in the head due to heater core hose dripping on it. Was able to repair it with a heli coil. Still holding up after 7yrs. Oil pan gasket developed a leak. Replaced. But after doing the solid axle swap, if it leaks again it will be a breeze to do now. Camshaft sensor went out. Engine would crank and crank until it started. Not too bad to fix this.

At 235k on my 02' Silverado ext cab long bed 8.1 w/ Allison 5spd. Love the effortless torque and simplicity of the engine. I've had cam sensor, maf dtcs and burns a little oil but besides that solid engine.

I have been a fan of the big block chevy since i was a kid in the late 70's. my uncle had a Chevelle SS 396 L78 4-speed car and a flat bottom ski boat with a 454 LS6 crate engine in it. both were super fast. once i was able to drive i got a camaro with a 350 small block but my dad would never let me swap it out. after i got our of the air force i found a 71 Camaro ss 396. not the most potent 396 ever made, but once rebuilt it added a roller cam and got rid of all the smog just, that thing was unreal. consistent 11.7's in the quarter mile on radials. there is probably another .5 - .7 seconds in it if i were running drag radials or slicks. was always festinated with the 8.1L vortec big block. it had a lot of high performance potential with right cam and better after market support.

I bought a 2003 gmc c6500 truck with an 8.1 Ltr with 124000 miles on it running on liquid injected propane. Now has 330000 miles on it. Just took a compression check to see if it was worth putting new injectors in it. 4 cylinders have right around 150 psi 1 cylinder at 148 psi and 1 cylinder at 161 psi. This is my work truck. It runs 6 days a week mostly city driving. Short runs all day long and once in awhile maybe a 50 to 100 mile run once a month sometimes well loaded. Unreal pulling power. Well worth putting new injectors in it. I am sure the rest of the truck will fall apart around that motor before it gives up. Only thing bad about it is if you think gas is poor fuel mileage, propane is half what gas is. But propane is cheap. the gross vehicle weight rating for the truck is 25900 and it is at its max often. Never has a problem pulling the weight.on the mountain roads of Oregon. I will run that motor until it dies but at the rate it going I think I will be First.

Love mine. California to NJ in 50 hours. Never missed a beat.

I just purchased an '01 Sierra 2500hd sle with 217,000 for what I thought was a very reasonable price not knowing a whole lot about the 8.1 except that it is a big block gm. Have to replace a few things on it like lf brake hose and the entire rear bumper assembly because it spent most of it's life in OR then the last 60,000 in MN. A bit rusty. Found it in FL and boy does she purr. After hearing your testimonial and history overview, I'm MUCH happier with my decision! I love muscle and this truck has plenty to spare in stock form. An ox in pony clothing! Thanks for sharing your insight! Much appreciated.

Just bought an 8.1 out of an 03 Avalanche to swap out my 6.0 from my 02 2500hd 4l80 4.10s , from everything I've researched should be a pretty easy swap . There is a book , Chevy 8.1 Vortec 496 performance manual on Amazon $25 , if you have an 8.1 buy this book , tons of good info .

There is an intake manifold upgrade most anyone can do for some free horsepower. You have to pull the intake off and cut the bottom off the intake manifold. There is a plate casted into the manifold inside that you can cut out and it will make right after the throttle body all the way to the back of the intake 50 % larger. You then need to weld the outer plate you cut off to gain access back on. The factory intake manifold stops flowing air at around 4000 RPM, This modification will allow much more flow and a smog inspection station will never know you did it.

I have a 2004 ‘Burb with this engine and I’ll never sell it. Pulls everything I have (up to an 8500# camper) and it gets the same mileage if I’m pulling or not. Beast.

Great video, the 8.1 builds have jumped the last few years. Hope the pushes for a better aftermarket. The Chevy 2500 Avalanche the 8.1 was the only option. My first was a 1500 started towing bigger trailers and purchased the 2500 installed 456 gears. Love 8.1.

I was lucky enough by chance to find for sale a 2001 Chevy CC dually 8.1L/Allison 4x4 with only 32,000 miles on it four years ago. Had it shipped to New England site unseen. It was titled to a courthouse in Florida and had a steel flatbed on it. Found a clean takeoff oem dually bed out of Texas and grabbed it. Still needs a paint job after years in the sun in Florida but a great running truck. Gas mileage not much less than my 2008 1500 5.3L. Kicked New England winters ass plowing the last few years. As far as the oil consumpsion goes, install a catch can system while blocking off the plenum under the intake manifold and problem solved. Spent years (5+) reading about and watching all I could about the 8.1 before finding this truck. Future classic! Edit: have a 2nd 2001 8.1L/Allison 4x4 164k truck for parts. Also grabbed by chance, can't go wrong there!

My auto tech class had one of these, It was a seized motor that my class took apart and actually learned on, however the other classes spilled the fluids and put a bunch of components inside of the engine along with food and pencils

I just picked one of these up from the pull your own part place for 225. Getting ready to drop it into my 93 2wd Silverado. And have a work/play truck

These things are great. A gen 6 cam slips right in and all you'll gotta do is change it to a gen 6 firing order in the ECU. Monster engine with monster power potential.

Just bought a 2002 3/4 suburban. 4 grand. And want clean. Mostly Rocker panels rusted out a little, only a knock sensor code. Runs nice so far

8.1s in trucks were also available with the zf6 speed manual along with the allison 5 speed

1. Oil consumption: mine was using oil and my mechanic pulled the intake bolts one at a time cleaned the bolt and the bolt hole then put sealant on the bolts and it stopped the oil consumption and fouling my plugs. 2. They are known to have problems in the 2001-2003 models with the crankshaft position sensor which can cause the engine to stall while moving but usually will start right back up, run ruff intermittently.

I currently tow a 5th wheel camper with an '04 Sierra with the 6.0. That engine does fairly well pulling 11K lbs. but grunts in the hills. I am now looking for something with more low-end torque and since I am not a diesel guy, I favor the 8100. The Alison trans is a bonus! But, trying to find one with a decent body and less than 200K is somewhat difficult. I love those Vortec engines!

Love my 04 GMC 2500HD 4x4 Ext Cab. 316,000 miles and counting. Transfer case has been the only issue. Replaced at 280,000 miles. Pulls as well as any Diesel I've ever driven with far less issues. I have beefed up the brakes and Suspension 4" life and pull 22,000# on the bumper. It has never been babied. It's kinda retired now, only gets about 5,000 miles a year on it pulling 2 of my heavy Antique JD (60 & 80) tractors to show & Tractor Pulls. If your ever in the Boise, ID area, chat me up.

My 2002 Avalanche 2500 has the 8.1 with 265.000 miles, runs great and will pull any think i hook it to, loves ice and snow also.

I had two of these motors in 37 ft searay for 10 years. Never a problem with heavy use. Compression was the same as when I bought the boat after 10 years.

I own a Bertram 31 with 2 of these 8.1’s and I love them!!!

I really appreciate the review. Thank you

I have this motor, my first 8.1 L has 45,000 miles on it, 2000 Chevy 2500hd, great BBC gas motor, though I prefer my 7.5 BBF motor.

Lots of industrial backup generators use this engine turbocharged and made to run on natural gas, or propane. We have one at my job. It's a big Ingersoll Rand

15 years ago I saw an ad in the newspaper ( how times fly ) just as the paper was delivered about 6 a.m. . I called real quick about a 8.1L for sale for $500.00 thinking it was a joke . It was real and the guy was a GM dealer mechanic that had replaced the engine under warranty and a bolt from either the crank or pressure plate ( can't remember for sure , it's been so long ago ) had gotten up and chipped a chunk of cast iron out of the block where the plug that seals the end of the camshaft . It wasn't leaking or even close enough to ever leak but GM did warranty the engine with a complete crate engine . I bought the engine over the phone and drove two hours to meet the guy during his lunch break . I was thinking it was a wasted trip all the way there knowing that either he had already sold the engine or there was a lot more damage than stated . He had the engine on the cherry picker and set it in my truck , i paid him and he told me how a bunch of his fellow mechanics had cash in their hands when he first showed up for work and that his word to save the engine for me was his word and if I didn't show up then he would sell it when he got back to work . I spread the word about the engine that afternoon when I got home and my phone was blowing up when I turned it on the next morning and I sold the engine before noon the next day for $1200.00 and a damn good old Arkansas country cafe lunch . I did notice numerous differences between the 8.1 and the 454's I was familiar with and learned later the guy that bought the 8.1 had a hell of a time dropping it in his 454 Chevelle . Great video sir .

I've got an 03 8.1litre, infront of a TH400/NP203/NP205, with Dana 60F, and a 14 bolt, w/5.38 gears. All sitting in a 1973 K10 shortbox.

Just got a 2001 Suburban with 76k mi. with the 8.1....so excited!

I know of several 8.1s with 400-600k miles all still run great. With 4.10s and a Allison in a 2500hd they pull just as good as a diesel

I can attest to the horse power and torque of the 496 8.1 I worked as a tow truck driver for a few years and the company I worked for used them in almost all their trucks most were factory propane fuelled or converted to propane but a few trucks were gas powered and the c7500 that I drove was a dream no problem picking up anything and climbing hills it sometimes felt like you were driving a giant Cadillac if you had a Car on the back heavy enough to dampen the springs in the back and it had no problem keeping up with traffic on the highway or accelerating from a stop light it wasn’t as fuel efficient as a diesel but maintenance was much cheaper than the diesel’s and replacing a blown engine with a rebuilt one was around $5000 and they sounded great

Very torquey motor. I special ordered my 4x4 with a 6 speed manual and twice broke my mounts. I'm on my 3rd motor mount replacement.

Got a 2005 ,GMC 2500 8.1 VORTEC ,ALLISON TRANSMISSION ,CREW CAB, LONG BED 4 WHEEL DRIVE ( ABSOLUTLEY LOVE IT ) HAD IT ABOUT 3 YEARS NOW , IT'S STOCK ,BUT A BRUTE , IF I WANT SOMETHING MOVED OR TOWED IT'S READY & CAPABLE ,BEST TRUCK FOR TRUCK STUFF I HAVE EVER OWNED JUST TURNED 144,000 MILES ( GET R DONE ) MY BUDDIES SAY TOU'LL BE DAM LUCKY IF YOU CAN MOVE THAT , GUESS I AM LUCKY ! I HAUL CARS ,SCRAP STEEL ,LUMBER , YOU NAME IT , SIT BACK LISTRN TO THE AWSOME BOSE STEREO , SET CRUISE ,& TOW HAUL ,& JUST DRIVE !! SOULDN'T TAKE 2 OF THESE NICE NEW SHINEY PLASTIC TRUCKS FOR IT , THIS TRUCK IS THE REAL DEAL ! WAS LUCKY MAN THAT OWNED A CABINET SHOP OWNED IT , FOR HIM & HIS WORKERS TO GET TO JOB'S ,HE OWNED ,HE DROVE ,HE MAINTAINED TRUCK ,HAD A 18 FOOT LONG ENCLOSED TRAILER FOR CABINETS ,ETC , INTERIOR & ALL GREAT A/C COLD ,EVERYTHING WORKS FLAWLESS , REALLY IMPTESED , LOVE THE ALLISON TRANSMISSION & WHEN IN TOW HAUL IT HELPS HOLD BACK WHEN SLOWING DOWN , ONLY FUTUTE PKAN , I WANT TO PUT DUAL EXAUST ON IT ! OTHERWISE LET IT EAT !! I PASS THESE NEWER TRUCKS ALL THE TIME STRUGGLING EITH A CAMPER ,OR TRAILER LOADED ,FRONT END LOOKS LIKE YOUR ON ONE OF THOSE HUMPD HUMPS AT A DRIVE IN MOVIE .( LOL ) WHEN IT SNOWS I FILL UP A LARGE COFFEE MUG & THERMOS & HEAD OUT REALLY JUST TO RIDE , BUT I DO USUALLY TAKE MY GEAR & MAKE SOME GAS MONEY PULLING PEOPLE OUT , I REMEMBER ONE GUY OFF ROAD ABOUT 30 FEET WHERE HE HAD DUG & SPUN & SLIDE DOWN ,HOOKED EVERYTHING UP READY TO PULL , HE SAID YOU GOT IT IN 4 WHEEL DRIVE DON'T YOU ? SAID NOPE HASN'T BEEN IN 4 WHEEL ALL MORNING & I BEEN THE ONLY SET OF TRACKS ON MOST ROADS , I SAID I WILL WAIT & SEE IF I NEED IT A LITTLE WHEEL SLIP AT FIRST , THEN WITH SOME FEATHERINGBOF GAS FOR OPTIMAL TRACTION ,UP & OUT CAME HIS DODGE HEMI RAM ,IT WAS IN 4 WHEEL DRIVE , HE WAS AMAZED, UNHOOKED DROVE OF STILL IN 2 WHEEL DRIVE ,OH DID I MENTION 8INCHES OF SNOW ON GROUND ,LIGHT SMALL FLAKE SNOW FALLING ,HAD SNOWED ALL NIGHT ! LOVE ME A WORK TRUCK ,& GOT ONE !!

Thanks for the information, very informative video. I just bought a 2002 3500 crew cab with the 8100. And yes the gas mileage is less than desirable and yes it does have an oil consumption issue. I have an issue on the # 8 cylinder fouling the plug. I’m hoping it’s a valve guide seal as it smokes badly on start up sometimes. It also has a periodic loud squeal after stopping at a red light and then goes away. I believe it’s a vacuum leak somewhere and it could be contributing to the spark plug foul. I bought the truck to pull my 24 ft inclosed Racecar trailer with a 3000 lb race car and tools air compressor generator etc. it does a good job. I’ll tear into it soon and figure out the oil foil and squeal.

I have one swapped in a 2002 Sierra 1/2 ton regular cab short bed 2wd with a 4l80. It is the most fun daily I have ever drove. It is my baby.

2005 big block with Allison trans has a 6th gear lockout, you can buy a kit to utilize the overdrive gear. The intake manifold is baffled down to a small opening along with a small MAS change and replace these gain nice power and torque

This engine would deliver a steady 300hp for thousands upon thousands of hours.

I still run my '03 Silverado 2500HD to this day after all these years pulling our large 5th wheel trailers. Current 5th wheel is close to 14k lbs. Fuel mileage is nothing to brag about but this is a very large engine with little design given to saving fuel. In town fuel mileage is going to be little over 8mpg on average and close to that towing in all conditions. Unloaded on the highway could average ~13mpg if given enough flat roadway. But it really pulls well and that's why we still use it, well that and new trucks are not given away. I'd say we've got our money's worth.

I got one 2003 silverware I’m keeping mine thanks for sharing

One more thing. I did this swap even though people said it wouldn't work. The 11.5 aam diff was very bad so I replaced it with a 14 bolt corporate. Paid 100 bucks for it.. lol. Same 4.10 gears to match the front. Which to me is one of the best diffs on the market. 40 years with only a few modifications...The only difference is you need a longer driveshaft. Everything else swaps. The only downside is you loose 1 grand towing capacity. Since the corporate is about 200lb lighter than the aam.

I have a 2001 Chevy Silverado 4X4 HD and I love it.. runs great and my fuel mileage is about 15-20 mpg depending on how I drive it. When I'm on it hotdogging it she burns more fuel, about 8-12 mpg..

This is the engine driving my 2004 National motorhome in a 2003 GM Workhorse Chassis with an Allison 1000 Tranny.

THANK YOU FOR THE LOW DOWN ON THE MOTOR / VERY HELPFUL / I LEARNED A LOT THANK YOU

I have a 2001 3500 dually with a 8.1 with a Allison trans. and I have 280,000 miles on it and it is a pull monster. I've had a 20' bumper pull trailer with a 580C case backhoe on the back and never felt it back there. I pulled it about 50 miles..

PSI makes a big bro of this at 8.8L with piston coolers, some blocks are SAE. Dart made a 4.5 and a 4.75" crank, large valve iron heads, 4bbl dual plane intake so you could run a carb & dizzy if you wanted. 8.1\8.8s are tall deck motors, like gm truck blocks. Aftermarket BBC rods and piston combos can fit. OEM manifold was a bottle neck. HO Marine units had a bigger cam, minimal smog parts,,,,more HP.

I had a 2002 Avalanche 2500 with the 8.1L traded it for a bigger bed but that thing would tow a 30' boat like it was a tool box

I have a 540 ci industrial version of this motor.plan to stroke and bore it to 621ci with conventional top end had to relocate some head bolts but not too bad

I've got a 2001 3500 extended cab Sierra 3500 with the 8.1 and still have my '78 Silverado dually with the original 454.

great video more on the 8.1 please!!

I got a very nice 2001 Silverado 2500 hd with this monster engine, it IS a Duramax Killer! I truly love my truck and in my opinion the 8.1 is the best truck engine ever built by GM !

Had a choice in 2002 between this and the “new” Duramax...I chose this due to the legacy of this big block and reliability. Bought an 02 2500hd GMC with the Allison and 4.10 gears. Best decision I’ve made on a vehicle! Tons of power and torque and tows trailers like a diesel. I tow trailers at 80 mph over one of the largest mountain passes in the west. It used oil from the start which a new recalled intake gasket helped. Also had a faulty crank position sensor that didn’t throw a code. But other than that, 300,000 miles later and not one issue! Half those miles were towing a trailer. Unfortunately, it just gave up on me last week...p0300 code along with crank and cam position codes... I’m curious where you got this crate engine? Looking for options if I can’t get mine running...

Marine 8.1 is the best out there

I have a 02 suburban 496 and still outruns my newer 5.3. the 496 has 312,000 and has never slowed down. Nothing more than suspension, radiator etc. 312k on the original starter, coils, transmission, power steering pump etc. I wish it would give up so I can blue print and balance it and get even more power out of it!

Gah - a brand new 496 Big Block Chevy! You lucky dog !

I have a 2003 2500hd, 8.1 .130,000 miles.clean as f*ck. Good truck. Pulls great.love tha Allison.

Larry the owner of Raylar Engineering who's a very close friend of mine put an 8.1 in his 99 Vette close to twenty years ago, shortly after that he started Manufacturing his cylinder heads

Trucks with this motor, early on any ways, had a larger tow capacity than the Duramax of the same year for far less money.

It’s a very popular marine engine too.

Belongs in the c4 with some good raylar aluminum heads, c3 big block headers will work for a regular big block swap into the c4, not sure about the vortec 8100, as you know it's an oddball, different heads etc.

I've seen one in a C5 vette before with a custom low profile intake. It's not particularly difficult to run it with an LS computer.

Purchased 02 2500hd w/ the 8.1 n the Allison trans. as a leftover in 03. Only have 145k miles.. first yr dealer replaced the booster.. otherwise with regular maintenance n an Xtra qt of 5 30 oil between oil changes, I'm xtremely happy with it. Using g it as a cement work truck , it was regularly pull heavy trailers with front loader on it with NOOO PROBLEMS. Always impressed as the Allison shifted going up n down hills with heavy loads. With light loads I found myself checking the rear view to see if the trailer was still hooked, cause I did t feel the weight AT ALL. Retired now so sold business but kept the silverado to this day. Would like to pump up the 8.1 mildly in near future without pulling it. Any suggestions. Was thinking modify the intake, gasket port n polish the heads, headers, n maybe a cam if possible without pulling it out. I just don't have the needed space. One car garage w/ z06 n harley.

These engines make more power than they're rated...a 162k mile 8.1 with stock manifolds dynoed at 412hp/545tq...headers raised it to 424/555

One guy who services irrigation pumps just took an 8.1 out of service with 40000 hrs on it...the equivalent of 2.4 million miles

My 2001 Silverado Crew Cab is my daily driver with the 8.1 and 6 speed manual transmission. We are now shooting for 400,000 miles next year on the original build from GM. When I retire in 3 years, she could have 450,000 all original miles. Yes I have had to change the spark plugs and the oil. I also have gone through two fuel pumps and a clutch. Brakes go without saying. My only issue now is lower body rust. I need to get that fixed! I wonder how much the old girl is worth these days?

I've got a f350 crew cab and I.also have a 8.1 out of a motorhome with 17300 miles my 7.3 needs lots of tlc you know inj cups clutch fuel sys weak so guess what oddball motor swap I'm planning nothing. gets going more than someone telling me you can't do that wish me luck I'll keep you guys posted ps great video

Have the marine version in my boat, great motor. Aftermarket isn’t great for this motor though.

How much is one of these engines used if you don't mind sharing that information

Just found one $400 everything in tact. Going in 86 C10

Bought a 01 2500 with 8.1 with 84000 now 235000 solid motor does have a drinking problem😂😂 had the Allison change and the mechanic said it really didn't need it if I get 500000 I will be very happy

I have a question for anybody that may get this I appreciate the knowledge of the guy that did this video he seems smart so now to my question I have a 1980 El Camino I have an old Schwan truck 2002 that is got the propane setup I'm wondering about putting that block in my El Camino and convert it back to gas?

8:00 People claim a 1987 Ford 300 inline 6 with 260 lbs-ft torque will pull a house off the foundation. They must be talking about a small 1000 sq-ft house.

have a 2005 2500 hd with the 8.1 with the allison have 260000 miles love this truck . oil consump problem found the best to run half 10w30 and haif 10w40 castrol our valolina does the best summer and winter this truck is my daily driver the cost of new trucks to maitain this truck keeping this truck if i find another one of this trucks and surburban i buy them and hold on to them

Gonna be mad at me but i always wanted to put a 3800 supercharged v6 in a c4!

Power solutions inc (i think?) still makes it as a bus engine. Supposedly it’s been stroked out to 8.8l.

I have 2 8.1s i am putting a 4l80 on the back but am having a problem with the converter fitting tight against the flywheel have you ran into that before?

Great breakdown of how things are different on these vortec motors. I have the 8.1 in my 2001 suburban 2500 and it has around 250,000 miles. Haven't had any internal breakdowns to date. You were so right in saying these motors are highly sought after, but they are also hard to find parts for too. One question because you seem to know alot about the different years of the vortec is about the throttle bodies. My 2001 has a throttle body, drive by wire, where wiring harness connects by 8-pin straight plug and I cannot find anybody, even aftermarket that sells throttle body with this connection. 2002 and up switched body style with an 8-pin plug that is more rectangular and connects on passenger side of body. I was hoping if somebody knew if I ever had to buy a new TB, can I switch to a newer model, with different plug config.? If so, how to I find out how to do a plug conversion? Would I have to switch cpu to a 2002 or newer. I may want to do some upgrades whenever I decide so rebuild, and this TB issue is a big pain. Any help would be appriciated.

Putting my 8.1 in my 78 trans am with 6 spd transmission

I have a 8.1 from a 2004 Silverado. Mine came factory with a6 speed manual transmission