Mobil 1 ATF in the transmission. ("runs cooler , longer")
THE CORRECT viscosity Mobil 1 gear lube in the rear end. (same)

'might want to throw Redline "Water Wetter" in the coolant after you
flush.

If you switch to Delvac 1 (Mobil's specfic fully synthetic Diesel oil) and
do a "baseline oil test" you may be able to run 10K miles between
oil changes (with regular oil testing).