Well, give the 302 gasket a try. I had so much trouble on my new 5.0 FR crate motor with GT40 aluminum heads that I gave up and converted to EFI using an Explorer intake. I tried to start the engine about five times after VERY careful sealing and fussing with the carb intake and each time all I got was clouds of white (water vapor) out the exhaust. And I tried EVERYTHING [period]. So, good luck.