Rear end gear replacement

[palallin]

First: find the rear-end ratio in your current rear. There were options available in our years; you may be able to avoid retro-fitting.

Sure-fire way to determine: pull rear cover. Count ring gear teeth (R). Count pinion teeth (P). R/P = Ratio (the math is left as an exercise for the student ).

I don't know which you have, but I'd bet there's a rear-end on a truck somewhere near you with a higher set.