Is the GN rear suspension/rearend the same as other G-bodies

[Jeff]

I have the wrong differential in my '87 GN, the speedo is WAY off, and it's not a posi.
I was wondering if the rear end and rear suspension on the GN is the same as other G-body cars (Cutlass, Monte Carlo, etc). If not, what are the differences?
Thanks,
Jeff

 

[REDS HOT AIR]

rear will fit from other cars but the turbo cars have a bigger rear in them with 8.5 ring gear where the others besides hurst and 442's have 7.5 ring gears.


sounds like someone might have swiped your big rear and swapped in a small one

 

[BUICKTR]

They could have change rear end gears. That would also throw off your speedo.

 

[turboman38]

The gear in the transimission that turns the speedo cable could be wrong also.

 

[Jeff]

Thanks for the good info...

The main reason I suspect the rear end is because of the yellow junkyard paint on the housing. You know the stuff they use to mark parts at the junkyard, I think there's a date on it or something, haven't looked at it in quite awhile. I'm finally able to spend more time IN the car instead of UNDER it....
The tranny is also an '85 BQ code from and '85 GN, and I don't know what gears it had, although 3.42 would have been most likely.
Jeff

 

[GNVAIR]

If your car is a theft recovery, then most likely the rear was yanked and replaced with a 7.5. This is not an uncommon thing as the rears are quite valuble and all the Malibu, Monte Carlo and El Camino guys want them for their cars.
Go here to see how to id a 7.5 vs an 8.5 http://malibunorth.freeservers.com/RearID.html