Commando pistons + '302' heads = ???

Well, it depends on how far above the deck the pistons are. If there .015 above, you can use a Fel-Pro .054 thick gasket and the 302's which would leave you with ,039, the same as a zero deck piston and Fel-Pro's .039 thick gasket.

That is a combo I have run before on a 360. zero deck pistons and the fel-pro .039 thick gasket and closed chamber Edelbrock RPM heads.

You could specail order cometic gaskets to the exact bore size and thickness you need. It'll cost ya a preety penny, but you'll be able to use those 302 heads and no get into a more expensive piston replacement issue.