[Killer Bee]

Warren, is it a C10 or C20? Keith posted 7k gvw options in C10 based on your post..

is it possibly 4.XX ratio 3/4t axle? I recall Keith posting recently about gvw groupings, maybe a factor here?

simplest thing to do at this point, is clean off a spot on the ring gear, mark a tooth with junk yard pen, and count..

if you can, do the same on the pinion.. maybe a mirror and light will make it possible..

compare your numbers to the factory options Keith posted and see if you're close..

if you're unsure due to access to the pinion teeth, count revs to see what neighborhood you're in..

good luck!