what rear end do I have, 3/4 ton 1969
 

I have a 1969 3/4 ton chevy with very low gears,I would like higher gears,what do I have and what can I use? Would appreciat any help. Thanks, RJ100

If it looks like this, it's a Corporate axle with the Eaton third member. The only gears you can get for 'em are 4.10's, 4.56's, and 5.13's I think.

you can get 3.9's from randys ring and pinion

If it is the Eaton, I would keep it ( do not tempt yourself to change axles). It is real easy to work on and instal new carrier. I just picked up one for 75.00 with excelent gears and instaled in one weekend (third member).
But they are my preference!

Jack-up the rear.Put a mark on thr rear housing nose and the yoke(lined up),and a mark on the backing plate and drum(lined up).Spin the wheel and count how many full turns the driveshaft makes to one turn of the wheel.After the last full spin of the driveshaft,see how far the d-shaft turns past the mark for the tire to complete it`s full turn.If the shaft spun 4 full and about a half,you have 4.56s.Five times and a little past,5.13s.Four times and a little past,4.10s.Then you`ll know what your options are to raise the ratio.Is your center-section round?That`s the Eaton HO52.If not,it`s a Dana60 and you can go to 3.73:1 with standard ring&pinion.

My 69 3/4 ton rear has coil springs, I am replacing coils with air bags. It looks like Roberts Picture,except with coils. What size am I looking for and where can I get Higher gears. It also has 4 speed trans. Thanks for all replies. Really appreciate the help. Ray, in WV

The highest gears you can get are 3.90s. It is a VERY stout axle. I would compare it to a Dana 70, as far as strength. I have one in my '68 3/4 ton. The only thing that I don't like about it is that they haven't been made since 1972, and the parts availability is limited... including higher gears.

I have 4.57 gears in mine. Someday I'll get ambitious and either change them out to 3.90s or put a Dana 70 in.