Factory 8.5 rebuild ????

[Streetbu]

G80 is just the rpo code for limited slip rearend, no matter the style

 

[64nailhead]

No G-body 8.5 (442 or GN) got a Gov-Lock. The Gov-Lock is a snow/slippery road posi. Every GN with stock power would've destroyed the Gov-Loc in a hurry. If your 8.5 is 58.5" from axle flange to flange and has the G-body torque arm mounts, then it's a rebuildable clutch style posi unless someone swapped in a Gov-Lock.

 

[pagrunt]

Sidebar: would someone be willing to post the year breakdown and ring gear sizes?
From my understanding:
10 bolt 8.2= early 60s thru late 70s
12 bolt 8.5(?)=early 60s thru late 70s
10 bolt 7.5 picks up where the 8.2 left off
10 bolt 8.5 does the same....
Is this close or can someone clarify?

10 bolt 7.5 started in '71 H Bodies (Vegas & clones), A/G Bodies in '78, F Bodies in '82.
10 bolt 8.5 started in '70 with F Bodies, Jan '72 A Bodies (replaces 12 bolts for certain mid level power engines)

 

[bertscova]

I found this set of videos whatcha think can this be applied to our rearends

Watch "Tom's Eaton Posi Tune-Up Tutorial (Part One)" on YouTube

Watch "Tom's Eaton Posi Tune-Up (Part Two)" on YouTube

 

[TexasT]

Sidebar: would someone be willing to post the year breakdown and ring gear sizes?
From my understanding:
10 bolt 8.2= early 60s thru late 70s
12 bolt 8.5(?)=early 60s thru late 70s
10 bolt 7.5 picks up where the 8.2 left off
10 bolt 8.5 does the same....
Is this close or can someone clarify?

There are several different "styles" of 8.2 I know the ones that came in a 68-70 Buick a body are difficult to get parts for and are not the same as other earlier 64-67 buick 8.2 ten bolt axles.

10 bolt 7.5 started in '71 H Bodies (Vegas & clones), A/G Bodies in '78, F Bodies in '82.
10 bolt 8.5 started in '70 with F Bodies, Jan '72 A Bodies (replaces 12 bolts for certain mid level power engines)

The 8.5 ten bolt in an Abody started in olds and Buick in 71 and had bolt in axles in 71-72 in those makes. Very stought rear until you get past 600 hp and a sticky tire.