Mike,

If Abe has the line on Mobil 1's nomenclatures that should be helpful.

As for the concepts in general, unless the engine is running "funny fuel" , the most important characteristic of the oil is it's viscosity. Assuming the previous owner is knowledgable of the clearances, and had adequate lubrication protection, that should be what you continue to duplicate. The additives play a smaller roll in racing situations as it's not common to leave the oil in service for comparatively long use. I would expect a significant amount of antiwear additive for camshaft protection, and some detergent/dispersant to keep contaminants ingested and internlly produced, in suspension for filtration purposes. If nitromethane or methanol are the fuels of choice, then the additive chemistry will need to be different than "conventional" oils as there are some chemical reaction considerations. Thus the different numbers Abe was referring to.