Rotella T 15-40

Rotella with the "triple protection" label on the front no longer has the zinc required to ensure proper flat tappet cam break in. They removed the zinc phosphate to prevent diesel "scrubbers" from getting clogged. Use the mineral based oil of your choice plus the comp cams or crane oil supplement. Once the cam is broken in, change the filter and refill with mineral based oil.

Once you have 500 mi on the engine, use the oil of your choice, mineral or synthetic without the additive. Some would suggest waiting 5k or 10k miles before switching to a synthetic to ensure proper "wear-in" of all parts but I don't personaly think that this is necessary.