kirban 2 cents worth
if you go with any conventional or snythetic oil available today the API reading will say SM. Unless you go with a special oil or a racing oil.
In order to have ample ZDDP levels to match what was in your engine back in 1987 you need to add a four ounce bottle of ZDDPlus. Alot has been written about the issues of current oils and zddp.
Our source has tested Lucas products and it lacks the levels zddplus has. Even GM cares enough about zddp levels. For example, our source had the original break in oil tested from a 2007 Corvette ZO6. That engine had 3,000 ppm of zddp in that initial oil from the factory. Well above the regulated 800 ppm of zddp that the current SM oils are permitted to have.
The company behind this product owns the largest turbo regal collection in the world. The product is carried by many of the turbo buick vendors including gbodyparts.com Jack Cotton, and us kirbanperformance.com to name a few.
It is the same product offered by 4 major cam companies, Isky and Crower to name two, major mail order companes such as Year One, National Parts Depot, Eastwood, etc and endorsed by Don Garlits.
We have had engine shops that build 1,000 hp race motors with roller set ups notice a reduction in wear using zddplus in the oil. So, while using the proper weight oil is important its also important to make sure you have the proper concentration of zddp added to the mix.
The issue is not just at break in.
kirbanperformance.com
denniskirban@yahoo.com
past owner of many 1986-1987 Turbo Regals and well versed on the
above subject.