[JIMs70GMC]

Some more usefully info:

Dana 44 8.5" ring gear front or rear, rear were mainly in leaf sprung GMCs(67-72) pre 72 in front had small 260X ujoint went to 297x ujoint in 1973. Dana44 last used in approx 1978. Semi-floating except front.

10 bolt(GM axle) 8.5" ring gear front or rear, this axle and a 44 in the front are relatively the same strength wise. And have some interchangeable parts. Came out in 1973. Semi-floating except front.

12 bolt(GM axle) I believe 8.75" ring gear. Used in the rear in 1/2 ton trucks 67-72. Not positive. Full floating

Dana 60 9.75" ring gear. Used in 3/4 tons out back from 67-72. In the front has 332x u joint. Was used it the front from 78-?.

Eaton rear ?-72 has a cover w/ 10 bolts and drop out center section. 3 different ratings with correspondingly larger ring gear. Not parts readily available. Highest gear is in the high 3s (like 3.90:1 maybe 3.73). Lots of low gears. Full floating.

14 bolt(GM axle) two versions full floating(FF) and semi floating(SF). FF has 10.5" ring gear came out in 73 in the rear of 1 ton trucks. SF had a 9.5" ring gear and was used in 3/4 ton and light 1 tons from I want to say some time in the late 70s early 80s.

Dana 70 also 10.5" ring gear as strong as a 14 bolt FF mainly in dually configuration not sure of the year.

FF- bearings carry load of vehicle(desireable) If axle breaks tire is still attached to vehicle.
SF-Axle shaft is intergal part of load carrying there for is subject to more stress. If the axle breaks there is a good chance the tire will leave the vehicle.

I'm going to double check this when I get home from work and correct as neccesary. Let us know what your looking at and we can go from there.

Welcome to the board! It's addictive!