Here is an interesting tech page I came across for those of us who run tappet cams. Most of us run GM Eos. Here is what I found. The quantity of Zinc and Phosphorus in ZDDPlus is FAR FAR greater than that of Eos. Take into account the bottle quantity and amount of each(Z and P) and the ZDDPlus is much better for out flat tappets. Now, depending on where you buy the Eos, it may be a little bit cheaper than the ZDDPlus, but you have to buy more Eos to equal the same quantities of Z and P in the ZDDPlus. It sounds like ZDDPlus is a far better deal and gives us better protection. Here is a link to the tech page I am referring to.
http://www.zddplus.com/TechBrief7%20-%20Oil%20Additive%20Dosing%20and%20Dilution.pdf

I am interested in TC's opinions.

Here is a link to a sticky over on Team Chevelle from a guy who has done a lot of independent testing on oils and additives. ZDDP Plus is well recommended along with several oils. It's 13 pages long but worth reading. http://www.chevelles.com/forums/showthread.php?t=195620

I use ZDDPlus now in my '68 Firebird’s untouched 400HO engine. After researching it and the ZDDP issues quite a bit, I decided it was the best alternative.

I did lots of research on this subject after losing a new cam.
I now use ZDDPlus and Brad Penn Grade 1 racing oil.

What if you used racing oils? :beers:

What if you used racing oils? :beers:

According to the ZDDPlus people, racing oil is not appropriate for day to day use. See: http://www.zddplus.com/TechBrief5%20-%20Racing%20Oil%20as%20a%20Replacement%20for%20SM% 20Oil.pdf

Racing oils typically don't have the detergents needed for prolonged use.

...racing oils typically don't have the detergents needed for prolonged use.
True!
Todays detergents allow motor oil to last 5000-7000 miles between changing.
Racing oils should be changed after 1000-1500 miles.
..But
Today's oils with detergent have less than 600ppm of ZDDP
Today's racing oils without detergent have 1500ppm of ZDDP
SF rated engines prefer 1600-2000ppm.
ZDDP wears out based on heat, and gums up your engine,
...so you should be changing your oil frequently anyway..

so YES,
If you can afford it,
I'd suggest SF or SG rated racing oil and ZDDPlus and a good KN filter and change it often.
...for me that's once or twice a year..

Yes, racing oils are definately NOT recommended for street driving, unless you plan to change your oil every 500 miles.