I have both to choose from. I'm going with dual carbs. One is paper gasket, the other looks like thick plastic with paper on both sides.

I ordered a set of the thick ones from AA. they were too thick, or rather the studs were too short. I had to use thin ones.

I have an unused pair of thick ones for 4 bolt heads, if you want them.
Zach

i think you might want to make sure your linkage will support the use of the phenolic gaskets. they 'push' the intakes out on both sides.

k

The phenolic (thick) gaskets are designed to insulate the fuel injection runners from the heads to prevent fuel from boiling in the injectors after shutdown. If that happened, the car won't start until the heads cool down. You don't need them for carbs, and they are probably detrimental.

Use the thin ones with carbs, and the thick ones with FI.

why and how would they be detrimental for a carb application? do we want the intake manifolds to become big further heat soaked items? would we want the intake charge to be hotter? why would jake and len be producing them? i use them with my webers and sure can't note any ill affects.

k

I have webers also and ran for awhile without the insulating gaskets. Here in 'Bama it gets hot in August, and I did have some minor restart challenges, so I put them back in. It seems to have eliminated the problem.