The decision on blank crowns or valve reliefs would have to be worked out. My thinking was that for a larger market group, pistons with no machining required may be preferred. Of course the blank crowns would work for the Chevrolet 250, or any piston that works in the other two engines for that matter. The 4 valve reliefs of the 307 pistons may work with the Pontiac 250 OHC. Note that the Pontiac pistons have fairly deep 2 valve reliefs.
