3/4 ton rearend info

[cnthandledizz]

I was wondering what type of rearend my 1970 c20 3/4 ton has. it's geared low but i dont know the gear ratio. all i know is its a 10 bolt with 8 lugs. and im thinking about doing a 5 lug conversion what type of rearend should i put in if you guys know

thanks

[Aarons72s]

It sounds like you have a ho52, ie the corprate, gm version, of the eaton axle. Is the cover round? and the center section unbolts from the actual axle and drops out like a ford 9"? If it looks like that it is an ho52. Does your truck have coil or leaf springs? If it has coils find a 71-72 half ton chevy with coil rear suspension, grab the axle and panard bar. Or you can find a 70 and just get some 5 lug axles out of a 73-82 chevy truck half ton 2wd. Or your last option is getting a 67-69 axle, but it takes more work to get 5 lug, the axle housing is shorter than the 70-72 housing. Oh when you do the swap, save the old axle. They are worth money because parts are hard to find and alot of us need the parts or the axle. Hope this helps.

[cnthandledizz]

do you know what type of gearing it has cuz it does look like a ford rearend, i was wondering if it had posi in it also

[Aarons72s]

4:10 was the highest avaliable gear, some had alot lower gears like 4:56 if I remeber corectly. Some 3:90 gears were avaliable aftermarket a few years back but they have been disapeared. It could, they were avaliable with a locker. Yah it looks like a ford rear end but it is built to last and lug a lifetime. Brakes are hard on these, drums are non existant. Shoes springs and wheel cylinders can be found but are hard to find sometimes.

[Aarons72s]

You might check your spid sheet, the sheet on the glove box door. It sometimes lists the info on if it has posi and gear ratio. You can pull the access cover off the rear and count the ring and pinion teeth for gear ratio and see if it has the locker in it. Plus I bet it hasnt had fresh oil in years if ever. The cover gasket is easy to come by, any parts store should stock it in the felpro line. Check the manual or ask the parts store for the correct oil.

[cnthandledizz]

so wut type of replacement should i look for

[Aarons72s]

Cheapest and easiest is a gm 12 bolt from a 67-72 with coils, I asume yours is a coil spring rear suspension, if it is leafs I am not good with leafs. You are wanting a half ton axle with five lug right? with this info and the info I gave you in my first post, If it has coils find a 71-72 half ton chevy with coil rear suspension, grab the axle and panard bar. Or you can find a 70 and just get some 5 lug axles out of a 73-82 chevy truck half ton 2wd. Or your last option is getting a 67-69 axle, but it takes more work to get 5 lug, the axle housing is shorter than the 70-72 housing. Because if yours is a coil spring rear suspension the half ton axle will bolt right in place of the 3/4 ton axle.
Hope this helps.