at .050 inch (whichh I undertsand is distance from base circle)
Nope, this is amount of tappet lift that the duration figures are derived from. I suggest that you go to www.compcams.com and look in the technical section and read the valve timing tutorial. This will help you understand what valve timing is all about. I don't trust anything in the Herd book, & I don't know who Colvin is. Also remember that factory HP numbers were more of an advertising thing than an accurate portrayal of the engine's power.
BL
