Quote Originally Posted by chevydrivin
......... we have some 90# in it now but only drive it less than 1500rpm and only about 1 or two miles per year, until I drop the rebuilt one in.
Ummmm........an SAE 90 gear lube is about the same viscosity as an SAE 40 motor oil, and the sulphur/phosphorous e.p. additive in gear oil is enjoying your rod and main bearings for lunch.