Rocker arm Geometry vs pushrod length

[IH 392]

I've seen tons of talk here on "pushrod length" but none (that I recall) on the proper rocker arm geometry, when there is talk of decking and such the talk always turns to pushrod length, the valve stem height has much more to do with "shimming" the pedestals than decking the block or head does (obviously heavy decking may require shorter pushrods for proper lifter preload, a lifter will soak up ALOT!), I've seen WAY! to many worn guides because an engine was slapped together with no regard to this, and with the Jeeps 8mm stems they have limited surface area. I've seen valves sunk into the seats on LP fuel engines over a 1/4" and the lifter has compensated for the change in distance from the cam to the rocker arm.
The "geometry" needs to be set and then pushrod length measured.
Here are some links that explain this subject.
http://www.compcams.com/information/Products/Pushrods/
http://www.circletrack.com/techarticles ... index.html
http://www.eatonbalancing.com/blog/2007 ... -geometry/

I'm not grilling anyone here, I just feel that this is a subject that needs some addressing for our engines

[John]

Geometry discussion also this 3 page thread: viewtopic.php?f=5&t=199&hilit=geometry
John