Rebuilt the B-440 engine that is in my '64 Plymouth, I Used HPL break in oil for the new internals/camshaft. Oil has been mostly sitting since break in with maybe another 25 miles since then. I am probably going to use a higher zinc diesel oil. Maybe HPL or maybe this. You think that it's too soon for a 100% synthetic and I should stick to group II possibly III oil? I have been mulling this one over for now or maybe the future.
Last edited: