Whats the approx max pinch point without tubes, on the x or j like heads and what are the benifits of trying to max out this area????

Thanks.

I have gotten a little over an inch, I try to leave no less than .040 at the pushrod wall. You can also trim the intake port divider wall to gain cross section. If you are doing a max effort job the pushrod pinch width wont be the same from port to port when you are done with most castings.

Thanks, then im close.

Im at 1.020, with the divider still looking like a divider vs very thin, ive read the average stock is .875 most these average close to .900.

Im gonna shoot for the 1.020 on them all, I think its obtainable.

Also did some of the early heads (x) have smaller pushrod holes then others???? Newer? Or maybe im just used to aftermarket al heads.

The pinch point "window" or what one would call it was 2.002 sq in before I started now its 2.371 sq inches.

Its an older time period correct build, not too worried about lower rpm area, 3500 vert/4:56 13.8:1, cam should knock it down, altitude will take its toll and so im trying to get all I can from these old X heads.

I also had to match the bores to the heads to get the right clearence,re shape the chambers as they are domes and .020 higher then they should be.

Ive never spent so much time on one set of old heads