I've seen a few questions on valve train geometry, 1.7 rockers, Porsche adjusters, etc. lately, including one that seemed to magically disappear yesterday.
We used to have a thread on it, but I can't find it, googleing I can find a download from this site, but it doesn't open for me.

Below is a link to an excellent thread over on the shoptalkforums and it should answer any questions you have on valve train geometry and it has some cool pics.

http://www.shoptalkforums.com/viewtopic.php?f=1&t=75703