Just bought a 77 D-100 with 440 auto. The previous owner installed an Edelbrock TM-7 intake using just the stock metal intake gasket. The problem I'm having is when it's fully warmed up, it won't stay running. I keeps missing and dropping cylinders until I bring up the rpm's.
I have always used the FelPro 1216 gaskets that sandwich the stock intake gasket when installing an aluminum manifold. Is it possible that my problem is a vacuum leak around the mating surface of the intake?

Some intakes will leak without the papers.We have ours that are aluminum installed with just the tins.No leaks.Just be aware that some of the thick papers will throw the bolt holes off.Easy to check start it and spray some carb cleaner aroubd the ports.Idle will change if its leaking.Rocky

We make some gaskets that are .015 thick, so they don't [Edited by Moparts - Family Friendly Site - Keep it clean] up the fit.

it might be leaking on the bottom side. I'd pull it & add a THIN/EVEN coat of Permatex #1 in the toothpaste like tube to both sides of the 8 valley pan ports

The carb is new with less than 200 miles on it, out of the box, so I don't think that is the problem. The guy at my local speed shop said that you can often get away without the paper gasket on the head side of the valley pan, but that you are asking for trouble if you don't use them on the aluminum side. After looking a little closer, I'm not sure the seller even changed the intake gasket when he put on the new intake.
For what I paid for everything, I basically paid for the new parts he put on and the rest of the truck was free! lol Gaskets are cheap.
Thanks guys. Merry Christmas.

Probably didn't - I have reused valley tins many times with out replacing - even when using an aluminum intake. cleaned all oil residue off and sprayed with a liberal coat of aluminum paint.

Back in the day they got reused a lot.They were like 30 to 40 bucks back then and that was a lot of $$$$.Ive reused them quite a bit with no sealer or problems.Both our BBs with aluminum intakes are run just tins.No problems.Intake is easy to pull and check for leaks.Rocky

While you have the intake off set the manifold down on the heads without the gasket and check the fit with a flashlight and or feeler gauges. There are some folks out there that still machine intakes to compensate for milled heads and that intake will ONLY fit the engine it was machined for.Unless that TM7 was fairly new I suspect that may be your problem Just something I have seen before
Gus

Gus, I've also seen them crooked new and that's what I mentioned in the other thread he started.

Link
https://board.moparts.org/ubbthreads/show...e=2#Post7516476

Look at all of the machining required to get it correct. It is amazing some of them actually seal.

Intake and carb were installed new and have less than 200 miles on them. Engine has 40,000 and has never had the heads off, so I don't believe anything has been milled. I used to sell auto parts for years and yes, I have seen many parts all fudged up right from the box. I am pulling the TM-7 and 600 cfm Edelbrock carb and bolting on a new Performer RPM and 750 Holley this weekend. I will re-use the valley pan and use FelPro MS 90175 paper gaskets. Should take care of the problem.