In an attempt to get rid of thoes swirl port heads, I have a set of 350 heads off of a 327 (dont ask). Ofcourse they are going to allow for more air/fuel and more exhaust getting out. Would they be too big?

 

Not a good idea.

 

Think we could expand upon this?

 

You will lose so much compression that any gains in flow will be negated. You would make even less power then you have now.

Also do assume just because they are "350" heads they are any good. Alot of 350 heads have huge 1.72" valves and swirl ports also.

 

Don't forget about the crapy 333882 heads that chevy made trillions of I have 3 sets sitting around, and one set is unproudly gracing the 355 in my T/A right now.

Even with .125 dome pistons the 355 is struggling to make 9.4 to one. Put a set of these on a 305 and you'll need a 6-71 just to get it started.