FSM calls for 20W-50, but that was 1971 dino fluid.
Would a modern 15W-40 synthetic protect just as well? I'll be changing before long.
60k miles, rebuilt Holley 4150 runs great and it runs WOT for ~10 minutes at a time on big hills, with manifolds glowing orange.
I have some basic 20W-50 in it now with a pint of MMO and a zinc additive for the tappets.
From what I've read here a diesel oil might be a good choice.
I have also heard that HPL BAS 10w50 is recommended.
Some might not know that the exhaust valves do not have seals - they are intended to "leak" slightly to guarantee stem lubrication under severe duty. There was actually a FSM warning builders NOT to install them.
Would a modern 15W-40 synthetic protect just as well? I'll be changing before long.
60k miles, rebuilt Holley 4150 runs great and it runs WOT for ~10 minutes at a time on big hills, with manifolds glowing orange.
I have some basic 20W-50 in it now with a pint of MMO and a zinc additive for the tappets.
From what I've read here a diesel oil might be a good choice.
I have also heard that HPL BAS 10w50 is recommended.
Some might not know that the exhaust valves do not have seals - they are intended to "leak" slightly to guarantee stem lubrication under severe duty. There was actually a FSM warning builders NOT to install them.