350 heads, and gaskets are completely interchangeable, side to side, and the gaskets can be turned upside down with no sealing problems. just do a straightedge check and make sure the heads aren't warped, and magnaflux them to check for cracks. 305 heads will bolt onto a 350, but the valves are too small, the ports aren't big enough, and the 58CC combustion chambers raise the compression too high for reliable running on regular gas. With premium fuel over 4 bucks a gallon and going up, compression gets to be a major consideration when building an engine!

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!