I had a 307 in my 69 Chevelle and amount of money I spent of building a performance 307 was a lot. The result I end up was replacing it with a 350.
Had I started with a 350 it would be cheaper in the long run. To do the work on a 307 it would cost the same of doing the same work on a 350. 283 and 307 were the same engine. 2 barrel, 1.72" intake *****ty heads, small cam. Just a 1/4" stroke. Get a 350 4 barrel and you already gain 100 Horsepower right off the bat. As 305 goes, it is no different.The motors are the same family. 350 is just cost effective. 350 are a dime a dozen in junk yards.
Last edited by lg1969; 11-10-2012 at 10:24 PM.