[stinger670]

I found a posi that came out of early 70's camaro,10 bolt 8.5 ring gear. The housing numbers are 410408N, will these fit my 10 bolt? Where can I check these numbers out? What should I be looking for? The unit is GM part, are they rebuildable? Should I be concerned with worn pinion gears?
Thanks guys..your help is greatly appreciated!!

 

[batman09]

I found a posi that came out of early 70's camaro,10 bolt 8.5 ring gear. The housing numbers are 410408N, will these fit my 10 bolt? Where can I check these numbers out? What should I be looking for? The unit is GM part, are they rebuildable? Should I be concerned with worn pinion gears?
Thanks guys..your help is greatly appreciated!!

do you have an 8.2 or 8.5??bm

 

[JBimmolate]

very good question

Miles

 

[stinger670]

Hi BM,
I have a 8.5, same as the posi. I think it should work but I hate to get it home and find out it won't fit. Can this unit be rebuilt?

 

[monzaz]

10 bolt 8.5 posi GM Factory

410408 is a 3 series factory unit
posi will hold all ratios from 2.73-5.57
rebuild info: yes they can be totally rebuild if you can find the parts.
clutches are still available in some after market shops: I have them for 160.00 OUCH!
Spider gears- I have only seen 3 different dealer part outlets have them. Each place had one set. 300+ dollars a set. So I would say after 6-7 years they might be gone. They were too expensive for me and the customers we had that wanted the rebuild and as you can see by now you can get a brand new unit for the cost of a complete rebuild on these units...Again IF you can find all the parts.

400.00 gets you an aftermarket posi that will likely be much better designed for performance applications.

If the unit is in good working order ..buy it and run it till it is done. Might last a pretty long time depending on your driving.

Hope some of the info helped:

More info to confuse you...lol

410409 is the 2 series version (2.41 -2.56 ) of the 8.5 clutch type unit and the internal parts are interchangeable from one to another.

There were a few auburn type 8.5 early units also available from the factory

The BUICK OLDS PONTIAC bolt in axle 8.5 rears also have 725 726 casting numbers that you may run across BUT they will not work with the c-clip axle chevy rears as the spider gears have NO recessed area for the c-clip retention. Again the parts are interchangable but you would only be able to use the clutches as the nova rear is c-clip...but if you put c-clip elim kit on the housing you could use these units.