CheezWhiz
Thread starter
i just picked up some 15w50 M1 from NAPA, it was on sale. Didn’t realize you could run it with a flat tappet, I have a 396 big block chevy and a 4.0 Jeep engine that might benefit from the same oil. Could consolidate down to only one oil for the GTO, K10, and TJ and then just buy Dexos 5w30 for my 6.0 vortec.