Quote Originally Posted by TheBear View Post
305s mostly had smog heads on them. Small chambers and bad combustion numbers. Thanks to Mr Nader. Older heads from 350s had much better flow numbers and weren't hindered by major emission mods. Major benefit was flow (more air and gas into combustion chamber) and less carbon buildup from lower emission restrictions.

other hobby 1320 junkie
All you need now is a stock cam and lifters out of a small block 400 and you would be ready.