56 rodger,and ted, you should both read the test results from stately labs of sparks nevada(now called ALS teck.Ted is close in his remarks but some difference in the test results. 56 roger is from another world which is fine.  the info i s[peak of was noted as 
diesel oil 'lab tests" and Wear test Results. speed talk. a very good read .if ether of you want i could mail you copy of some 30 pages of results.just send me your mail address to ct1940@shaw.ca..
my first job was in a loging camp,they used only series1 engine oil for gas and diesel engines. my car was a 1955meteor 272. I had axcess to free oil changes used this oil for years,sold the car with 100,000 miles. never had to even set the valves,checked them and under the valve covers like new.this ws in 1957and series 1 oil was a detergent oil for diesel engines.But modern diesel lube oils are entirely a different animal and not to be used on gas engines, especially flat tappet cams.
 hear we go again on oil discussions,but what better to do with our time(some times in the past


2shaw.ca

About 12 years ago I got 20 one gallon bottles of Delo400 15-40 from a neighbor and I have been running it in my 223 six in my F100 truck ever since, engine had about 40,000 miles on it and now  has about 70,000 miles using it. So my question is, if it causes problems with the cam what is the difference in a diesel cam? Old diesels would run 200-300,000 miles with no problems..

Given the following, I'd say that most diesel cams are nitrided, along with other components subject to high contact pressure.

http://papers.sae.org/2004-01-1448/

The Germans were probably doing it in WWII or before.

5/30pennzoil ultra 115612psi before break down
rotela t    (10w30 valvoline nsl 105000 break down
71214 psi at breakdown new retell t 15w40 72022 at break down.
dello 400 5w40 69631 at breakdown
info from speed talk re test info diesel oil and gas engine oil tests

I've read several tests on the break down, I don't recall if the Delo 400 that was tested was the new synthetic or the old conventional. I'm using the old conventional 15-40. I'm not concerned about the lower break down on a stock 223 six, If I had some wild cam and high valve spring pressures I would. I just used the last of the old conventional on my last oil change, so I'll be looking at using something different in the future..

other things that may contribute to cam failure
oil with low breakdown#S
no presure in rocker shafts(90% of rockershafts i have dismant for re use had gauled rocker arms as well as worn shafts. reason is bleed off tubes. ) my take is no bleed off, block them . the oil leakage will work down to dist gear and time chain.
the gaulimg of rocker assembly must be hard on cam and lifters

just read this post man 56roger your a guy after my own heart.could not have said it better.my whole live has been thats not the way everyone else is doing it.get lost.