Need Help with my '75 Monza rear end ID...

[CableDroid]

Hey guys, I recently bought a non running '75 Monza factory 5.7 car. It's missing the torque arm, but I am curious on what the rear actually is. It has 4 non threaded holes on the center section for the torque arm attachment, like it would need 2 long bolts. I read that all Monza are 7.5", this one has either 3.42 or 3.55 gears with a clutch type posi. Since the car is 40 years old, who knows what has been changed. It has 4x4" axles...

The letter/numbers stamped into the passenger side axle tube is 'K-122'.

I attempted to attach pics, but the site is telling me they are too big. I will see about a 3rd party hosting and post the link.

Any help is welcomed and thanked in advance.

[CableDroid]

http://www.cardomain.com/ride/4064467/1 ... olet-monza

[hammerdown7]

That does appear to be a stock 7.5 from the torque arm bolt flanges. It has a non-stock rear sway bar. The R&P ratio normally was a 2.29:1. The tooth count of both the R&P should be stamped on the ring gear near the teeth as well as the face of the pinion.

Dick

[CableDroid]

That does appear to be a stock 7.5 from the torque arm bolt flanges. It has a non-stock rear sway bar. The R&P ratio normally was a 2.29:1. The tooth count of both the R&P should be stamped on the ring gear near the teeth as well as the face of the pinion.

Dick

Thx for your help. Obviously someone changed the gears at some point. It appears that it's a factory clutch type posi, but I think it's been rebuilt based on the condition and color of paint on the clutch springs. The whole unit in general seems to have been setup very well.

I just ordered a pair of Yukon 1541 axles (26 spline S10 axles) and will have the stock drums redrilled for the time being.

Now I just gotta find a stock torque arm since mine is missing.....

[monzaz]

10 bolt 7.5 rear the Posi is CONE Auburn Not clutch unit. The only clutch type units that were in the 7.5 factory rears were S-10 Eaton Gov locks.

It all appears to be stock. Unit appears to be stock also Not rebuilt... Normal stock color of the GM springs for posi units are WHITE. But the oil adheres to the spring along with metal silt as the spring creates a magnetic field collecting garage to the coil over years of compressing and rebounding same with the axle shafts. Rubbing metal will tend to create this occurrence. Wipe the spring with a cloth and see what is under the goop.

Jim
J D

[monzaz]

Oh and I might have that torque arm you need... from the trans to the rear. Jim