hey I run a combo like that.
used a 92 nv4500 5 speed with 3.55 gear.
yes, lube is a few $ and NEEDED! GL-4 only.
IMO,5th gear issue seems to be 4x4 heavy towing in 5th gear lugging the engine. not read to many failures on the 2x units other than wrong type of lube.
I think it is a blast in my 85 stepside. :drive
everyone says it is no good for hot rodding but I beg to differ.
holley 650 spredbore dbl pumper
holley STREET Dominator intake
Hughes whiplash roller cam
hedman headers/2.5 duels 2 chamber muffs dumps at the steps
9 1/4 - 3.55 lockright locker
29x9.5x15 mud tire
18+ mpg 1800 rpm @ 55 mph