$50 Craigslist 360 EXTREME budget rebuild??

Just fire the thing up using thin oil 5W-30, oil will get to everything quick, and you will see great oil pressure.
I run 5w-30 in about everything, my 360 mag scares me sometimes on start up hitting 75-80 psi, with a .010 crank and stock mellings oil pump.
I know your clearances are not optimum, but you want oil to hit everything right now on the initial start up.