I was wondering if all year 350 heads will fit the 305 on my 85 trans am, and if so does anyone have any that they need to get red of, and how much will the 350 heads wake that car up?

 

If I'm not mistaken, because of the smaller 3.336" bore on our 305's, 350 heads wont work too well. World Products has a set of S/R (stock replacement) Torquer 305 heads that I'm thinking about getting. Check those out.

 

Don't do it.

Because of the 305's smaller bore (3.735), when the combustion happens the flame meets some 90 degree angles (on the top of the deck). It's really hard for me to explain but I hope you get the picture.

You will also lose compression because you are going from 58cc heads to 64cc heads. Thus a loss in power.

 

Wait till you get a new motor and go with a 350 or 383 and some good aluminum heads like AFR 190s. Stock 350 heads don't really flow that much better than yours unless you mod the hell out of them.