What are your thoughts about types of fluid to use to prime your engine as you rebuild it? I have heard from a friend to use the Blue STP Oil. I guess, just apply it to all the bearings and cylinders, lifters, etc. Then add normal 6 QTs of oil.

So what do you think? thxs

 

Everything should have been assembled with some sort of moly assembly lube, aside from the cam which gets cam break-in lube. Simply prime with motor oil, but stop when you see oil coming up out of the pushrods/rockers, otherwise you'll blow all of the moly lube out of the bearings.

If you don't have a roller cam, make sure to use oil with high zinc content, or a ZDDP break-in additive. Good oils would be Valvoline VR-1, or any CI-4 (not CJ-4) compliant diesel oil. To my knowledge, Valvoline Fleet-Guard (which is also rebottled under Napa's house brand) 15W40 is the only diesel oil left still running on the CI-4 spec, which still has an adequate amount of zinc left in it.