Heres a great idea--I do think slow, ha ha--pop the heads off and have them milled down and make sure they leave the face of the intake side alone. You might want to take a few pictures to help them dedice how much to take off.
This way your compression would go up a bit- thats nice-and the intake would fit-to that motor only. Guess when in doubt, have them take off the min., check it out, and if it needs more, take it back to your local shop.
Thicker gasket would be cheaper but this way here you gain a 1/2 point or more in compression