I have a set of 882 76 cc heads that I would like to put on my lg4 305. I have previously re-worked the 882's, and I imagine that if I could get the heads around 62-66 cc I would gain a fair bit of power. I would like to know how much the heads should be milled and how much the intake should be milled to accomidate the changes in the heads. (I can no longer afford to build up the 350 until next winter) Thanks for any responses.
also, the 882's have 1.94/1.50 inch valves, will the milling cause clearance problems with the 305's smaller bore? Thanks again.

 

Forget the 882's for a 305. They flow poorly even when ported and the combustion chamber sucks. By the time you mill them down enough
to get decent compression ratio on a 305 the will be so thin, they will likely crack.
Sell them off and start with a small chamber
performance head like L-98's or vortecs or
late camelbacks with bolts holes. Or even port a set of 305 castings. I ported a set of "416's" and got good flow numbers for a budget street head. expect around 225 cfm@ 28
which is plenty for a street 305.