Well I had a set of tapered aluminum blocks that I installed over the finned heads. I had to mill a slot across the fins to put the tapered blocks. I have no Idea what the angle was. I then had to angle mill the valve reliefs for clearance. All this was in the learning experience. Then I purchased an angle table that allowed me to do this with out tilting the mill head. (***** to tram in). Now there's a machine shop in town that has a head broach with a 12" cutter. I put a .040" shim under the piston side of the head and take off .050" for a street engine on 8BA heads and a mild cam. You'll have to use a die grinder to clearance around the chamber for some piston clearance. If your running a high lift cam (over 350 net lift, you might want to do some pre measuring. Anyway, on the 258 engines tis came close to 8:1 CR. The same for 59 heads. Some guys filled the transfer area with braze. Today this is very time consuming. What works almost as well is to just mill the heads for .045/050" clearance. I forgot to mention, you had to run a 1/2" drill down through all the bolt holes. Just remember one thing , it had to look stock. Now I think the air pressure in the right front was more important.
