Two oils that are highly targeted towards these engines is Joe Gibbs Hot Rod Oil and the different flavors of Brad Penn oils, both also have excellent break in oils, I'm using brad penn break in oil and brad penn 15-40 because of the extra clearance we put in the main and rod bearings, I used to think some of the diesel oils were the way to go, but not so, diesel oils are made for a large bearing surface and soot caring ability, gas engine oil has a much higher bearing shear protection because of the smaller bearing surfaces in gas engines.