Oil line plug/ low oil pressure on cold starts

From the sources used in the articles linked below, the engineering studies did not find an increase in wear even at the lower concentrations tested. Even 800 ppm ZDDP antiwear package is better than these engine generally got when new. Once we get into high spring pressures for high lift cams, then I think its best to consider the 1200 ppm as the minumum. In my cammed 340 I'm using Brad-Penn (I think its been renamed) 5W-30. You could use their oil as your car has no cats. In my stock rebuild AMC Wagoneer I used Ford Superduty 10W-30 for Diesel Powerstroke because it is a conventional oil with decent ZDDP level. Then switched to Fords 5W-30 semi-synthetic that has just about 800 ppm. But the Wagoneer has a cat so I wanted to go for enough but not too much. But you use what can find convenietly in your price range. Its just getting more difficult to find oils like these on the shelf.

Widman has an excellent overview of engine oil.
Grant's review focused more on history of ZDDP.
Both cite and quote primary sources relating to negative aspects of long term use of zddp above 1500, particularly these two:

“Cam and Lifter Wear as Affected by Engine Oil ZDP Concentration and Type”
Loren G. Pless, John J. Rodgers, Fuel & Lubricants Dept., Research Labs, General Motors Corp. SAE Report 770087, 1977

“How Much ZDP is Enough?” R.M. Olree, (GM Powertrain),M.L. McMillan (GM R&D) SAE Technical Paper Series 2004-01-2986, October 2004

Grant and Widman's articles are directly hot linked to pdfs.
The SAE papers cited are available only to members or by purchase. Probably also available at most engineering college libraries.

This post on IFSJA has a couple snips of an article from Engine Professional magazine. Apparently the stuff comes in three forms.
International Full Size Jeep Association - View Single Post - Our older engines and newer oil is not a good mix


Hopefully someone else can provide some more insight into those Lunati lifters.