Here's another place to get ZDDP oil additive
http://lesfrickshun.com/Several 'local' old time machine shops recommend this product for all flat tappet cams. It's about $8.00 a quart and one qt is needed per oil change to sub for one of the normal grade. Pretty reasonably priced as compared to most of the 'racing' oils.
I've been using it for a year so I don't have any real proof of how it well it works - yet. I figured it to be relatively cheap insurance for the cam.
I looked into the Joe Gibbs oil, which everyone I've spoke to claims it is great product, but figured that for the price I could buy a new cam just about every 5 oil changes. I thought for that price I should be paying for a guarantee, not insurance.
