How To Identify GN Posi Carrier

[skylarkstage1]

I am in need of your input. There is a party locally that has for sale a 8.5 " posi with 3.42 gears which, he says, came out a GN. I need to know how I can determine that it did indeed come out of a GN and is a 8.5" carrier , not a 7.5 or 7.6". Thanks in advance for any and all input.

 

[Lee Thompson]

here you go !!!

About half way between the center section and pass. side backing plate--front side of tube ( toward eng.) there is a code stamped on the tube.
I believe these to be accurate.
1984---6TJ--non posi
6TP--posi

1985---8TJ--non posi
8TP--posi

1986---2TJ--non posi
2TP---posi

1987---3TJ --non posi
3TP--posi

These would be for ALL turbo Regals

 

[skylarkstage1]

Lee, it's just the posi with gears, not a complete rear end.

 

[KevinB]

To start off, the 8.5" are 28 spline. The 7.5's are 26 spline.

 

[supercrackerbox]

Sorry to bump an old thread, but at least I searched before starting a new one . . .

Reason I bumped is because the big swap meet is coming this weekend, and one thing I'll be actively seeking is a posi unit for the 442 8.5" rear in my Regal. I know I'll need a 3 series carrier. So if I see someone with a posi unit sitting on a table next to some rusty Chevy parts, how can I positively determine whether it will fit my rear?

 

[pacecarta]

read this ..even has pics
http://www.buickperformance.com/posi.htm


took less than 3 sec to find on google

 

[supercrackerbox]

Excellent, thanks!

 

[charlief1]

To start off, the 8.5" are 28 spline. The 7.5's are 26 spline.

Even though this is an old thread I will add that this is not the way to tell. I have a factory GM carrier for the 7.5" axle and it's a 28 spline. They do come with 28 spline in some cases if it's out of a later model vehicle.

 

[G NASTY]

Are the non posi and posi housings the same? I bought a 3tj one and planned on building a spare rear with it. Putting a 8.5 rear with 30splines

 

[pacecarta]

axle housing are the same, you can pull an open center section (the part with the ring gear) and replace with a posi center section (transfer the old ring gear to it )
if you go to an eaton 30 spline posi center section you will need 30 spline axles as well as new larger side bearings and races for the carrier (also called w/spool bearing option in some install kits)
if you order axles get the street axles for c-clip they will slide right in
race axles have a larger diameter at the outer bearing and require the MSR-9000 c-clip elims