Join Date: Oct 2003
Location: on the road in NE Oklahoma
For over 10 years/50,000 miles I've used both Mobil 1 75w-90 and Mobil 1 75w-140 in the LS rear end and transmissions ( T-10 and a toploader) of a '66 GT350 recently sold. Fairly severe duty with many high speed endurance runs of over 100 miles each. No leaks, no measurable wear, and no shifting issues. Any high quality synthetic oil is going to be a major improvement over conventional oil in the friction reducing department.
looking for '65-'68 manual V-8 coupe
that doesn't need a new body