Are 305 heads worth putting on a 350 engine. The block is a cast#: 3892657 1964-1967 two bolt main. From what I can gather online, the heads are a cast# 376450 1975-1981 and have a 60cc chamber. with these heads restict the engine or will the small chamber help the compression ratio. I want to build the engine for a street machine but i don't want to get too radical, I still want reliability and longevity. I will be placing the engine into a 1978 Chevy 1/2 ton short-bed pickup.