tedster is on the right  trail.2years ago i sent 2 members a survey on modern engine oils,a engineer in ca tested many brands of oils results wher interesting. his summary is modern oil for flat tapes  lifters are fine for blocks and other flat tappet cams. the hot rod preacher received i package with all the tests. diesel lub is a absolute no fn way for flat tappet cams. it is designed for roller lifter diesel engines using low sulphur diesel. in fact the cat dealer i worked for sent memos to employees do not use rosella t on flat tappet cams(the bulk cans  of shell even  hade a caution (do not use on gas engines.
most block issues wher from  poor oiling to top end. if you have 1/2 the rockers getting  little or no lubrication  you loos camshafts,wear rockers and rocker shafts. my present 292 with 4vmanifold dura spark  sign,many miles blocked bleed tubes at rock shafts,idels  hot 20 psi 4000 rpm55psi,engine was freshened 12000 miles ago burns no oil(the od drip from valley cover). used pennzoil 10 40 never had to adjust valves.
OIL IS LIKE RELIGION/ OR POLETICKS EVERY 1 IS A EXPERT. NO 1 WANTS TO READ THE ENGINERS REPORT. JUST COULD NOT STAY OUT  OF THIS BULL SHIT ON OILS THAT SAVE THE DAY

No, just so there's no confusion here what the engineers are saying is adding an aftermarket bottle of miracle zinc to the crankcase may cause more harm than good. We're not oil engineers so we kind of have to take their word for it.

I've been running a stock Y for 20 years now wouldn't it have shown up already?

You make a good point. Add the zinc to regular oil and ''DON'T WORRY ABOUT IT", like they say in New Jersey and New York !!!!
Late,
Tim 
Waiting Room For Heaven, Florida 33706

It would seem an easy inexpensive solution is to use whatever modern oil one prefers, and simply add a small bottle of the ZDDP additives available.

Except, oil engineers strongly caution against aftermarket additives. They point out that motor oil additive packages are carefully blended by the manufacturer, and that third party additives can cause problems.

I've decided not to worry about it, a stock motor as I have w/ OEM camshaft has mild spring pressures and aren't going to have the risk. If it were a problem, it would have shown up by now.

Greetings , I  swear by Brad Penn in my  Mummert 292 for the last 13 years .
The motor has  finished  seven  la Carrera Panamericana  & four Chihuahua rallies and has  never been  rebuilt .
These endurance rallies are long 10-12 hrs a day  ( LCP = 7 days  & CH = 3 days ) and we push all day .
and have managed to always finished  1st or 2nd in class .
see their web site  and available thru Summit , Amazon  etc 
giddyup
 

I think many of these issues may have been true only at the time of discovery. Change one thing with the chemistry or metallurgy and undesirable issue crops up. Then the chemists go back to the drawing board and fix it. An example of this was when Shell Oil tweaked the formula by adding more phophates to their aviation oil, elevated copper levels suddenly appeared in everyone's oil analysis reports. I am remembering this from about 25? years ago. The point is, Shell was quick to address the problem but sometimes past issues never die.  A problem is discovered then corrected but the legend lives on forever.


64F100 57FAIRLANE500

In the mid 60s I freshened up (hone, rings, bearings, chain) a junkyard 57 Merc 312 to put in my 48 Tudor. That engine didn't have many miles on it but the cam had heavy wear and galling. I was a college student with no money to spare so I pulled cams from used 57 y blocks and every one of them was shot! I gave up and went to a Ford dealership and bought a replacement cam and lifters cheap, 246* duration I believe. A month or so later a friend offered me a new 290* "blower cam" and a pair of G heads with big exhaust valves that turned out to be 56 intakes for $25. I changed cams without changing lifters.
 I bored the block .060 and installed 1/4' deflector pistons in the late 70s. The cam and lifters were perfect. I was using Kendall GT oil. After break in on 30wt ND I used 20/50 VR1 for a few years before switching to Mobil 1 15/50. I have dual valve springs and I don't remember the specs, but the cam is still good judging by the valve lash not changing.
I also have read bad things about ZDDP additives. Who knows?





"FREE SAMPLE"

All oils are formulated differently for different application. When cams started going flat the hi performance cam manufactures blamed the lack of ZDDP in the oil rather then their off shore made cam and lifter blanks. And with a combination of heavy valve springs it was a disaster. I can't remember ever seeing any one with a stock Y loosing a cam, and if they did it was probably from a reason other then oil. Any oil today, even the worst ones have more PPM then the oils of the 50-60s and we didn't lose cams back then. Racing oils aren't formulated for street use, run a race dump the oil, they lack detergents and other chemicals that are formulated into street oils. Some rocket scientist decided that with the panic of less ZDDP that diesel oil would be good to use. Have you ever seen what the high detergents in diesel oil do to cast iron cams, lifters and cranks? They can formulated this way because diesels have steel cams, lifters and cranks..
I personally just use Valvoline 10-30 conventional in all my 50-60 cars and I have never had a problem after countless miles..

I only mentioned Valvoline VR1 because of the vast amount more of zinc it contains, like, just for information. I too read somewhere not to use "racing oil" in street vehicles due to short oil life.  Of all the engines I built, I lost one cam due to no crown on a new lifter. Something very easy to check, a hard lesson learned thousands of years ago. But back in those days, I believe ZZDP was part of oil formulation. Fast forward to now days and modern synthetic technology,  I wonder how necessary this is, except for the purpose of initial break-in. I have to laugh, years ago when I owned, flew and maintained an aircraft, we had these exact discussions about the same exact thing only we called it "hangar flying."  Many brands of aviation oil all claiming to be the best thing since sliced bread and yes, there are snake oils offered for aircraft use also.


64F100 57FAIRLANE500

I have never lost a cam in one of my engines and I have used every brand of oil you can name.  I have probably built two dozen engines in my life, ninety percent of the them had solid lifter cams.  I did see a bad cam once in a neighbor's scruby engine.  Given that, one can see how there could be so many different opinions on oil.  I suspect bad cams happen due to poor installation, incorrect break in procedure or from using used lifters.  If the cam in my TBird wore out, it would mean I would have to remove the engine, turn it upside down, buy another cam and a set of expensive lifters  I will do anything to keep that from happening.  If I had to, I would use $50 a quart oil.