THE ULTIMATE LS3 HEAD TEST-STOCK VS CNC AFTER MARKET REC-PORTS 

Pay attention folks. Richard Holdener doesn't sell out to anyone. He brings hard factual data. Hard data that will never be presented in other avenues that are slaves to advertiser money. Thank You Mr Holdener!!!!!! Been reading your tests, buying your books since the Silver State Notch😁

Brother I wonder if people realize how time consuming the testing you do.I just figured out that the magazines I used read the tech articles years ago were written by you.Much respect my friend..

This was the video ive been wanting to see. Those Gm performance cnc heads actually made more power than i thought they would. Thanks you Richard for all your hard work and excellent content! You are the man. By you doing all this testing, we see what does what , and it saves us money, time and headaches by using wrong parts and combos.

Soon as the rocker ratio changed, the results were out the window and not comparable to the others. Yes, the mast would be right up there but you can't fairly compare those to the others with having more lift. I know guys bust your chops about using the wrong cam, lol, but i think the test definitely coulda used a bigger cam with that amount of cubes. Besides the Mast heads, you proved the difference between all the rec's, great test !

Love seeing the tests iv read about years ago on video. I remember a lot of details but I'm a visual learner. Way better now.

Looking back to a serious cylinder head test-amazing effort! The Mast heads appear to be attuned to the 0.661” lift as they drop off a bit at 0.700” lift. So the lift was probably a big factor. But Richard, we need to compare this LS 468 to a 0.060”-over 454 with optimized heads, cam, and intake! And while you’re at it, include the overall weight of the package. I’m sure you’ve got the data in your archives, so let’s see it!

I'd love to see an updated test that includes the AFR and TFS LS3 heads.

I want to congratulate you for channel and thank you for taking the time to do everything you do to share us top notch information, better than those magazines

Been trying to catch up on all your videos man keep them coming 🤘

The mast heads out flow all the others across the board, so the higher peak power is not just a function of the higher lift, but it does help. Thank you for sharing all of this info!!!! I was kind of waiting for this but lost patience and sent mine out to Frankenstein.

Badass testing. Thank you! What mad scientist have they got at Mast that came up with the (by far) smallest port with the most flow - that made the best power? I've long been a fan of Darin Morgan cylinder heads, and would have liked so see something by him. EDIT: I swear I wrote that first part before googling and learning that Darin is now working for MAST. I guess now I know who that mad scientist is!

Now I want a 468 cubic inch LS

thats alot of effort....and great test overall. I subbed you for all that effort and useful info. nice job....and I am a Ford guy

Thank you a ton, was doing a budget build on a 2010 Camaro and decided to keep the heads the way they are. Going to move that extra money toward a stall converter.

The extra lift isn't going to add the much more HP on the Mast heads. The little taller deck and port making it a better flowing head is why it makes more power. But those heads are big bucks.

As always you have a habit of separating the wheat from the chaff. For my money on a 5.3 or 6.0 ls I would probably stick with the stock heads and limit camshaft lift to around 0.550-0.580. At these lifts spring life would be reasonably good on the street and more lift with the stock heads probably would not appreciatively increase the hp very much. On the street I seldom took street motors much past 5500-6000 rpm and rarely ran more than 9:1 cr. Ran all my motors on reg or unleaded gas. I’d leave the valve timing up to those more knowledgeable than me. Would I produce tons of hp. Nope. But I’d have a dependable play toy I could beat on for a long time. Thank you for your debunking lessons. I really do enjoy them. Keep making them and I’ll keep watching them.

It would be interesting to see how the cathedral port 245's would compare to the mast LS3 heads with lift being equal.

Just looking at the flow numbers, The West Coast Cylinder Heads did not drop off in flow as the flow increased. That is a good thing, even if you are not using a cam with lifts above 0.600". It indicates the flow will be even better at low lift when actually in operation.

Thanks for this rich, I was about to pull the plug on some prc heads but I’ll just stick to the milling my stock ls3 since my build is mild at best

Richard, you're amazing. You present and speak very well, you let the data present itself, and you seem completely independent and unbiased by 3rd parties. For example, repeating that the FAST intake shows almost no gains, all the aftermarket heads don't offer too much more over stock LS3, etc... From my watching your first vid I clicked, I was hooked. You are enabling people that want to do some research and planning, to save a lot of money, and allocate their $ toward better improvements from a value and return perspective......all for free. We thank you immensely, and when it does come time to spend $ on dyno service or such, I will now gladly look up Westech first in an effort to repay what you have given to the performance community. Contributing to others is very non-selfish, and one of the highest achievements possible, thank you.

Your last line got me: "... then add boost!". Brilliant ;^)

Great info here, Richard

Love it, the last 30 seconds was all I needed though. Thats what she said!

The Mast heads were designed for the big bore motors. The power was not just from more lift.

Old guy told me, (intake flow)x2+10%=max horsepower possible. I'm assuming that's for NA apps. Nice job, as usual. Thanks Richard! 😁

This video helped me a lot! I've got a 02 Camaro and am building a 6.2. I've sold the rec port heads off of it because I knew it was just getting a set of pistons. Now I feel that using my Cartek 243 heads was the right decision. Hopefully I can make 650hp.

Richard, you are a legend! Thanks for throwing on those afr 245s on a big engine. They were never designed for an engine that big but they did hang on good for what they are. They were only 20hp down from the mast heads which is not much different. If you go on AFRs website they are designed for 416-454 engines. Mast do you have the best ls3 heads though IMO. AFR's Ls3 head is also very good too. Great test. One of my favourites. Another suggestion, reach out to Tony Mamo and get one of his reworked trickflow LS7 heads. These have made 700rwhp through a manual trans corvette along with his ported MSD intake.

Free thumbs up for great titles. My favorite was battle of the borgs. But this is up there

I have heard good things about the Liberty heads once they have been ported. They are VERY inexpensive and more than cover the cost of good port job and quality valvetrain.

I think that the extra lift on the mast heads had a lot to do with the more power. Most of the time the more u open that valve the more air u will flow which translates to more power!

Would’ve like to have seen how Texas speed ported ls3 heads did but not at all taking away from your work. Lot of time and work when into this. Thank you for your very informative videos

Excellent just like the last test. Thanks again Richard for all the time & effort, that was awesome. Much respect to you & the gang. Cheers

I'd love to see some more lt1 action maybe ported lt1 heads vs lt4 heads or forced induction

Top notch information

Good video 👍

I think the fact that, on the Mast head, the valves are opening 10% faster accounts for the majority of the performance gains seen. I'd be interested to see an engine test with different rocker arm ratios, and the difference (if any) on idle vacuum, and the avg hp / tq for said engine..

Hi Richard love all the Videos. What difference would a LS7 head make on this engine?

Awesome!! I can see you are getting closer to test ls3 heads vs ls7 heads. You may use this same short block and cam. That's going to be really interesting!!!

interesting results I'm going to use LS3 heads after seeing this ill just get mine touched up and smooth out the ports and go with that

Thank you so much brother!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I would have liked to see the mast cathedral port head that was designed for large bore/displacement engines tested.

Love your style!

The 1.8 rockers allowed heads to get deeper into high flow lift numbers and spend more % of valve open above .300 lift

Would love to see some test on torque for these "LS3" heads. I've got both an LY6, and a L96 truck. They work for a living. We need truck torque tests!

Can you please test out Edelbrock's E-CNC renctangle port heads for small bore Cathederal port engines?

Great videos I'd like to see a comparison of flat plane crankshafts against a standard crankshaft, where do you gain power or loose.

Awesome. Well done 👌

I would have liked to see the SDPC heads run with the 1.8 rockers to see how much they added and to compare to the Mast heads.

At first blush, I would have thought just the rockers would have pushed the Mast heads over the top, especially when you consider these heads peaked and fell off sharply sooner than the rest of the heads ... however, there's always more to the tale. Looking at the flow numbers of the Mast heads, they outflow EVERYTHING on the chart by a large margin throughout most of the flow chart. It's no wonder these heads produced better results than the other heads. They would most likely have done that with 1.7:1 rockers, just not quite as large a gain.

MIND BLOWN 🤯 damn those ls3 heads are good

Helluva nice torque curve with the fast and im assuming factory ly6 would be close i really dont think more lift is the key more than likely itsthe extra flow in the 3-500 area

Man i learn more from u than i have any other channel so thanks man keep up the good work lol if you ever wanna test a motor in my fbody your more than welcome haha

That Cathedral heads has air velocities. And what rpm you going shift and how far down the rpm it's going drop after shift. So much more factors. I still learning. Good info Richard. Thanks

What kind of power do the Mast or AFR heads make on a 6.0 with similar set up? Great videos by the way. Thank you.

Fantastic!

Richard. I would like to see all the truck cams comparisons to see which comes out on top. Such as Tick, BTR, and Texas Speed. They all have different specs and just would like to see the top "overall" grind.

Damn Richard, you are the best..

I really appreciate your time and effort to do all of this testing . I don't know much about poring heads and after watching some videos I realized how little I really knew. I remember hearing a fellow replaced heads on a ls7 with a set off a ls3 and the car did a lot better off the corners , road racing .

Thanks for the info. Is that 1 3/4" headers?

Quick question Richard.. the largeish cam you have in this big cube LS. How would it run in a smaller 6L combo with something like twin 75mm and big boost? Too big? Rpm too high? It would have forged rod/piston but stock crank. I know you used the stage 3 btr cams in the big bang tests, think that kind of size is better? Wanting around 1500 wheel hp. Your channel is flying Richard! Ive shared it up all over the place lol.

Richard please forgive the lack of knowledge, but have you done an episode testing TFS220 Fast as Cast heads on a 6.0?

I want to see some Texas speed heads, and gwatney performance heads

You should try a little more duration on the intake side. The ported head looked very promising

Wish this was done on a stock ls3 bottom end. This is a badass comparison

Guess those 1961 Chrysler long rams really were the ticket for street motors besides the cool factor of having the carbs over the shock towers. :-)

Arg you had to throw a bomb in there right at the end. LOL I was set on buying a set of refurbed LS3 heads for my truck. Will still probably since I am installing a LSA blower. Your LS3 intake with adapters video showed that those adapters are not the best. Thanks for another great video. PS ever done any LSA blower tests?

Is there more to the story than WOT power production? Do the heads notably influence drive-ability or engine responsiveness at part throttle?

The Mast head made the most power because of its mid lift airflow advantage over all of the other heads (between .300 to .600). Just goes to show that Mast really did their homework when they designed that head.

So good!!!

Thanks for the continued testing. Is there perhaps a misprint in the head specs chart for the Average Torque on the stock LS3? It shows 483.1? The CNC version can't possibly be over 110 ft lbs increase can it?

The problem with stock LS3 heads is valve drop you need PTV clearance to get the most potential of these heads and big lift duration cams are limited for stock LS3 heads

GM cnc ported Ls3 heads a good choice for BTR STG 4 cammed sbe street ls3?

First, I really appreciate this gentlemens testing and efforts. This stuff makes us all better. But my two cents is....... Although something to be learned there. Without trying similar cams except with very different valve lifts. Say .550 .650 and .750 lift ranges. It makes it hard to digest any power curve test results. I have not picked up the calculator to see if its enough. But maybe 3 sets of rockers. Like 1.4 to 1 up to 1.9 to 1

I wonder if the Mast heads would still have done the best had you used a 1.8 rocker on all the other heads

It's summer time Richard. You need to take a road trip to Parker, or Havasu for inspiration, and research. Cold Beer, Skimpy Bikinis and Hot Boats. How about some BB boat motors for our Flat Bottoms, and Hydros. Every guy with a boat tinkers on the motors in the winter. They have families, so money is a budget thing. Mopars, Chevies, Fords, in every size and shape. Just an idea.

Fast EFI manifold VS Blow thru single plane manifold. Same engine, turbo, intercooler, and boost lvl. Would be interesting to see the different power curves, and if the added cooling from the blow thru would make more power. Good stuff

Please help, I have TSP 228/228 600/600 112LSA cam kit 660" dual valve spring kit PRC titanium retainers TSP 7.400 pushrod kit TSP rocker trunion upgrade kit w/intake exaust valves on stock non-ported heads. Also, 102mm TB with FAST intake. I need some down low HP/TQ. I have the $ for heads and fuel pump. I heard RHS matches with FAST intake. But my cam?

GMPP cnc ported ls9 heads are where its at. They flow 340 cfm, and come STOCK with titanium intake valves and sodium filled incolnel exhaust valves. Never miond the thicker deck and stronger casting with a better alloy.

If you were running this with E85 on the street, a road course or even a 1/3 mile oval car, the efi intake would probably be the way to go. How much torque this makes your gonna have issue on the strip and the 30hp will show up every single time.

A stock LS3 head can make 700hp... that is wild.

The dr j was impressive, for a street car with wcch heads would be sweet. The mast heads seem like they needed more cam

2019 6.0 in my 2500hd is such a turd down low. I bet putting on some Cath port heads would increase low speed torque production. Whatchu think?

What happened to the Mast dyno run that you had to cut it off at 6700 rpm? All the others ran out to 7000. Did the valvetrain go out of control, and are the 1.8 rockers to blame? Yes, the higher ratio rockers helped the Mast heads. Higher ratio slightly increases duration, in addition to the increase in lift. And because of the higher lift, the port is operating at higher flow numbers throughout the valve event.

For me I prefer power in the low range with lots of low end torque. Unless you are all out racing, twisting the engine up to 7000 RPM is rarely seen in everyday driving. I like to have fun in my hot rod and that doesn't include driving around with 4:56 gears turning 5000 RPM on the freeway.

I'm a Ford guy that loves stroker Windsors with Cleveland heads, although the Ford does make good power it is not nearly as easy or affordable as the LS platform. GM hit it out of the park with this design. I'm just curious what the new direct injected engines are like, better or worse??

Whats the cast number on factory LS3 heads

@Richard Holdener, any possibility of doing a heads or cam test like this on the Gen V LT1?

I'm in the process of building a stout shortblock for my Silverado and im curious just how much of a difference you'll see in going from a 3.6 stroke to a 4.0 stroke in an LM7. would love to hear your thoughts. oh, and yes I would be selecting a different cam for the longer stroke engine but I wouldnt be changing the heads. I'm more concerned with power below 6500 being that's where a street truck will spend most of it's time and obviously have more weight to move.

Great video. Looking forward to the SBC version. I know you have the data... Results should be a lot more dramatic, considering that the stock SBC heads are not in the same league with stock LS units.

Badass test; my TFS 225 R's from TEA are in the ballpark with the Mast LS3 head. My exhaust port out flows all in the chart @ 282 CFM at 700 lift. Going on a 430 windsor, 13:1 cr motor that will run on corn. I wonder why race/pump gas was used instead of corn? Was it because the test was done back in 2010? just a thought as I saw the date on the file tab and maybe E85 wasn't available as much in Socal back then? Anyways good test.

AFR and TFS LS3 heads, please.

I’m thinking a solid roller with 270-280 duration and .700 or more lift would’ve widened the gap much more at the top.

Did you have to change the push rod length with the mast heads?

What kinda power 09 6.0 e1841p make with uncapped injecters

Sounds like a good setup for my 6.0 thanks! You should do a test on bbc peanut port heads In stock form (no removing the heads) then change springs out do another test, then gasket match just the openings of the ports and blend (no porting or removing heads) and run another test showing that you can take peanut port heads and make good bottom end power all the way up to 6000 rpms with out removing the heads.

Man I was really hoping you tested the trick Flo heads

I really wonder how the engineers at GM ever managed to get the LS3 head past the bean counters. They basically put a race-quality cylinder head into mass production.

Thanks for the video. Could you discuss the bumps in the torque curve at 4900 and 6000 RPM?Is it intake runner length? The injection manifold had torque bumps at 4200 and 5200.

After seeing the gains with the 1.8 rockers I have to ask what the gains on factory heads would be with those rockers.

Low speed performance for the win. unless all you do is 1/4 mile racing. In my opinion on the streetyou spend way more time at slower engine speeds than twisting it as fast as it'll turn. But, what do I know.