? Valvetrain Geometry ?

Thanks for the comments. Unfortunatley many engines are built by people who don't check any of this the first time (like me when I was 18). Unless the problems are extreme, the engines run... for a while anyway.

I always had some assumption that a $600 set of "cool looking" rocker arms sold by a leading performance company would "fit" and work perfectly (regardless of which valves, mahine work, springs, etc... I had). In fact, that is the trap that speed magazines used to snare many of us with in the past. "So-n-so did such-n-such with these killer parts and made a zillion HP so go right out and buy these parts!!!" A lot of the more popular magazines today do a much better job of giving true project results and good tips/checks to do when trying stuff yourself. You just have to expect that no two re-builds are ever exactly the same, even if stock! Stock rebuilds can just live with a lot more slop than performance engines can.

The bottom line is as you stated. Assume nothing, check everything, and add 10% minimum to your build budget for the extra "fixes" you will need to do for your specific setup.