The camsahft has nothing to do with displacement.
The bore & stroke plus the number of cylinders determine the displacement.
To make a 305 into a 327 you would first have to bore the block to 4", which isn't advisable, or maybe even possible, then put in a 327 or a 307 crankshaft with the proper pistons.
It would be much simpler to make a 350 into a 327. There, all you have to do is change to a 327 crankshaft and pistons.
P.S. As an afterthought. it just occurred to me that you could put a 400 crankshaft into the 305 block and you'd get about 328 cu.in. It wouldn't be much of a performance engine, in my opinion.
Last edited by johnnya; 01-23-2006 at 12:01 PM.