Guys!

Thanks for all the responses. Yes, the geometry question is a fairly complex issue. Of all the articles, books, materials I have read on this subject my favourite one has got to be the one I've attached to this post.

I also agree that simplyfing it by only looking at the rocker arm to valve tip alignmnet is merely addressing part of the issue. However...for my build I am really not going to change much else...so if the center of the shaft is off in relation to the valve stem tip (horizontally speaking) and the full sweep of the rocker arm nose does not make a perfect arc. with a great 90 deg. at half-lift...well, so be it, because correcting this would require more extensive work/re-work that is simply not in my budget for these parts.

What I can control however is the alignment, and it's really by means of either using the shims (Hughes Engines) or the valve stem cap.

I have never ran caps in the past, but for a non-roller rocker they do certainly increase the area where the sweep contact is made, which means the pressure is distributed better and the valve tip itself does not take the "beating" otherwise. The opposite is true (even more so due to the materials) for the rocker arm itself...

Great ideas, I will probably pull the springs on 1 cylinder and try to do the full-sweep pattern check with just a checking spring. I had actually done this a few months back before I pulled the heads, this is what the pattern looked like with no use of the shims or caps:





The sweep mark was too far to the rocker nose-tip for my liking, so by elevating the rocker (shaft shims) I was driving towards a more centered mark on the rocker nose. The valve stem tips on the other hand were a little too far towards exhaust, which seemed to have matched what I was seeing on the rocker nose itself.