i just read in another post someone put the 305 heads on a 350 for more compression. is that a smart idea and would it get more power out of it. in my swap i'm not rebuilding the heads just cleaning them and the 305 heads have 135k on them. with more compression i'd probably screw them up wouldnt i?

 

The difference between the 305 heads and the 350 heads are that the 305 heads are double hump heads. Look at the front of the head. There will be a raised notch sticking out, one notch if it is a single hump head and two if they are double. Double will give you more compression, however they have smaller valves, 1.94 intake. The thing to do is to have the valves bored out to 2.02 and this will give you a good hp increase.