megaladon6 said:i don't believe as much transfers from the 307 to a BOP 350+
While those with Chevy blinders on may find this hard to believe, there's no such thing as a "BOP 350". There are Buick 350s, Olds 350s, and Pontiac 350s. Nothing interchages between them. On the other hand, as noted, everything except the pistons and rings will interchange between a 307 and 350 Olds.