How to install an Intake Manifold on 5.0 Ford Foxbody Engine 

That’s great to hear! I always hope they will be a genuine help to my viewers.

I’m glad you are getting some use out of them. Thanks for watching!

Thanks! I hope it helps a few guys!

I would definitely not use and did not use RTV on the gasket surfaces. I used Permatex High Tack which is a specialized adhesive used to hold the gasket in place and promote sealing on the side of the gasket without a print-o-seal surface. This is essentially the same product as gasgacinch which is what Ford recommends for this job. Applying an oil or grease product to the gasket can damage its integrity and is not a good idea. As for retorquing the manifold bolts, that isn’t possible with an EFI manifold unless you remove the upper and I have never seen it be necessary if you follow the procedure that I outline here.

I probably have stills of all of that. Try DMing me on Instagram at @tecmotiondyno or message me on Facebook through the Tecmotion Chassis Dyno page and I will see if I can find them for you.

Thanks. RU-vid is a great resource for this kind of thing, but the quality of advice varies. I try to post things that I have a good deal of personal experience with so that there is a good resource available.

@@tecmotiondyno you are the ChrisFix of mustangs 😂 just kidding, you have much better advise.

Glad to help. Good luck with your install!

This is a totally fair question. Ford do not specify anti-seize or a lubricant on the bolts and the torque spec is dry. With dissimilar metals, anti-seize is normally a good plan, but you need to be aware that it could reduce the torque spec. I looked up the installation procedure for a modular Ford which uses aluminum heads and steel bolts from the factory and Ford do not specify anti-seize or a lubricant in that application either, so they clearly expect that you will install the bolts dry whether the heads are iron or aluminum. The way I did it is definitely according to spec. Anti-seize may be a good idea to prevent corrosion, but you should do your own research on torque differences.

Glad it helped. Thanks for watching!

Yes, a vacuum leak is a possible outcome of a bad manifold installation. So is a coolant leak or an oil leak at the China wall. Another possibility is that one of the vacuum lines or fittings that you can’t see well under the upper intake has come loose or apart. I have even seen problems like internal leaks in a component- for instance the membrane in the EGR valve can fail and cause a vacuum leak inside the valve itself. A high idle that absolutely will not come down is virtually always a vacuum leak somewhere.

Sounds like it!

Just use right stuff on the China Wall and in the corners where the heads meet the China Wall. Use Permatex High Tack or Gasgacinch on the head side of the water passages and at a few small strategic locations to help hold the gasket in place during assembly and to improve water passage sealing. Do not apply an additional sealer to the manifold side of the gasket - the print-o-seal is all you need there.

Studs. You can cut the heads off some long 5/16” NC bolts if you don’t have studs.

A smoke machine can be very useful. Sometimes wd40 or ether will help find intake leaks - if you spray it around potential leaks and get a little idle-up you may have a problem in that spot. You have to keep in mind that you can have an internal leak on a part too. For instance, if the diaphragm in your EGR valve is torn, you can get a leak right through the valve even if the vacuum line itself is ok.

​@@tecmotiondyno Thanks!!. couple of more questions, for a performance modified engine like the ones showing in the video, how you know the proper inicial timing? Ford manual say 10 degree but there is not stock cam, also the stock ECU can handle this modification or the ECU need to be chipped? thanks again

As a rule of thumb most aluminum headed EFI Windsor style Fords respond best at around 30* total ignition timing at WOT. Setting initial at 10* will yield 26* total with most Foxbody Mustang factory computers. I always add the rest by reprogramming the computer with a chip, and to get the most out of an engine like this it should be tuned on a dyno. The factory computer can handle a shocking amount of modification when competently tuned on a dyno, and that should really factor into your project’s budget from the beginning.

They don’t specify locktite and it takes some effort to hammer them in. If they came out, it could be bad, but I’d put that chance at very remote if you hammer them in right. I think of them as being similar to a rivet.

Permatex don't specify a minimum application temperature in their data sheets, but do say the minimum temperature range for storage is 46*F. I generally try to use Right Stuff at temperatures above 60*F. You will probably get away with doing it at a lower temperature, but I would keep the gaskets and hard parts together in the same place so that they are all at the same temperature, then maybe bring the RTV out of a warmer place like the house just before applying it. You could call the Permatex technical line toll free at 87 PERMATEX and discuss the situation with them too. The rest of it can be assembled cold, you should just keep all the pieces together so they are the same temperature on assembly.

@@tecmotiondyno thank you for your fast and detailed response! You're videos are great. Subscribing now.

It is my first choice of intake for a street driver with good heads and a good cam.

@@tecmotiondyno have a 331 with Promaxx heads and good cam .. was running the Tubular GT40 Intake but def got lost in high Rpms ..hope to make some extra Power above 4000 rpm..

The GT40 works well for stock or near stock motors, and for AOD cars that won't shift high anyway, but for a Mustang with a manual and a decent cam and heads, you need more intake, like the RPM 2, to unlock the potential. Long tubes help in the upper RPM's too. My Mark VII uses the RPM 2 with a TFS stage 2 cam and TFS track heat heads, and 1 5/8" long tubes. Coupled with a Lentech Street Terminator valve body, it is a good combo.

@@tecmotiondyno L have that RPM2 intake on an all fine ..went for a ride and Terminator X adjusted all very nice .. Datalogs look verry good ....cant tell if more power or not ..car was running strong also with the Tubular ..I need to change the Tires because this 255 Cooper cant handle anything ..1. gear is terrible and and in 2. it starts to spin tires from 3000 up to 5500 ..had the timing at 27 deg max ....will put some Drag Radials on and try again ...and I hope to get a better feeling ..

The passenger side one is the one with the biggest issues. You need to remove the filler neck baffle and then grind out the baffle bosses. There are some bosses along the edge which sometimes need cleaning up too. Use a die grinder, then when you have the job done, test fit the valve covers and roll over the engine, remove them, and look carefully for any witness marks on the rocker arms or valve covers just to be sure you did it right. The advantage of this is that everything fits with the stock covers, but as soon as you put tall aftermarket covers on you have a myriad of clearance problems on the outside with your throttle linkage, hood, idle air valve and so on, and every way you try to manipulate it to solve the problem can easily introduce a new problem. With a motor like this, I think it better to just modify the valve covers and then everything else fits.

Good question. I used Sunlight dish soap with tap water and turned the heater on. I did a lot of fasteners like this, and it either cleans them up or preps them for an easier cleanup with a brass wheel on a die grinder.

I’d have to see it to have a real opinion. A machine shop cleanup might be possible. Junking it and using something better might also be a good idea. If it is not severe, the gaskets may work as is.

I've seen people get out all the corrosion, fill in the low spots with jb weld and sand smooth. If you're in a tight spot

Cut the heads off some long bolts. There’s a similar question in the comments on this video and I posted the size and length I used in answer to it, so the specifics should be easy to find here.

5/16” NC thread.

Fel Pro 1250S3. They are the same size but have a steel core and are a better gasket. They block the EGR passages though, in case you planned on keeping that system.

@@tecmotiondyno Thanks! I’m using the non-compliant 1399’s so the EGR is history.

Definitely use 1250S3 then.

Using the Right Stuff... how long to let it cure completely in a 50 degree F garage?

Mine are just bolts with the heads cut off. An automotive supply store can usually supply long studs that will work too.

@@tecmotiondyno great idea! Thank you

@@cooperzappacosta8234 We found it was easier to find threaded rod at the hardware store

You might be right!

@@tecmotiondyno it makes a difference…I did it. I got an extra cart that I don’t stack stuff on lol. It’s the service cart. It helped my back a lot since I was dumber when I was younger. Lol

The older I get, the more painful it is working on this stuff!

I don’t even think this is a regional term - it’s derived from the curving wall like shape of the block in this area which resembles the Great Wall of China.

You just find a bolt the same size the intake uses at the hardware store but maybe a inch longer and then just cut the head off with a cutoff wheel.