[west coast]

So it looks like there is no real standard of what lift you should measure valve overlap. Since i have a comp cam i will kind of fallow them. It sounds like you should use the numbers for tappet lift done during advertised duration which is .006. i found the web page that had the formula's that John Dinkel posted on here which work if your cam card reads valve timing at advertised duration which mine doesn't it is at .050. So now on to understanding all the theory's behind all of this.

Dale hope my costly mistake will save you money. Its hard to explain the problem but a picture is worth a thousand words that will leave you speechless sometimes.