chevy 305 heads

i was thinking of getting a 1977 trans am with the olds 403 motor and restoring it. I wanted to up the compression ratio to get more power, and was wondering if the heads off of a 305 motor will fit the 403 block. if anyone knows it would be a great help. thanks!!

i have put a 305 heads on a 400 sb. there was some differences in them. but to me the easiest way to up the compression ratio is to just get a higher compression piston.

Or an aftermarket head with small closed chambers (provided the stock pistons won't smack into them or the valves). MUCH more powerful than OEM 305 heads.

I think a 403 is a big block and a 305 is a small block
so no it won`t work. the easiest way is to get your 403 heads shaved at a machine shop or even better
buy some aftermarket heads.good luck