I also finally got around to replacing the fan belts, and putting in Amsoil synthetic 20w50 oil and gear lube. I've been running 20w50 dino oil till now. There is still a slight leak from the front main seal, but I decided to go ahead and do the oil now. Engine seems to like it. Runs nice and smooth. Hard to say if it's a genuine improvement, or s psychological one, but I like it. Shifter is a little smoother. I'd tried Swepco oil before and it made the tranny really notchy, so I went back to synthetic ATF. The Amsoil stuff feels good, probably comparable with Redline.