Oil weight

Scroll down on this link......

http://micapeak.com/info/oiled.html

Now, please note that this info is dated. I checked last year and heard that our wonderful government has limited zinc once again. Rotella use to be good but they pulled more zinc out of it. The "specialty oils" (not for street use) they left untouched. I use to swear by Rotella but on my last build I started using Valvoline Racing oil (speciality oil) because they haven't screwed with the zinc amounts.

Brad Penn oil is a winner, scroll down and read about the ZDDP results.
http://www.penngrade1.com/Zinc.aspx

Flat tappets "live" on zinc and die without it. Do the research or start saving for a rebuild. The sure cure to all these problems is to go to a roller cam.