Heater Box gasket kit

[chevyrestoguy]

I am restoring the heater box for my '64, and a long time ago, I bought a gasket/seal kit that I finally opened last night. What a joke. The foam gaskets are paper-thin compared to stock. Even my original, nearly 50 yr old gaskets are about 3 times as thick as the new ones. I want the foam seals that are the stock thickness. The cowl seal barely sticks out past the lip of the flange. If I installed this kit, my truck would have dozens of air leaks. I want to have a tight seal everywhere, and this kit is not going to cut it. The company that produced my kit was called Repops.

Any suggestions on a good quality (thick) seal kit?