IFS Gears
Postmaster
Joined: Jul 2001
Posts: 4,038
Likes: 3
From: South Kitsap County, WA
The front is a reverse cut 8.8... the aftermarket gear catalogues shows these are available in 3.73s, 4.10s, and 4.56s. The rear can be either an 8.8 or 9.75, and it doesn't matter which engine you have, contrary to popular opinion.
Not quite sure on the positive identifier (bolt #s and shape of cover), but the truck comes from the factory with the tag hanging off one of the bolts. It has the ring gear size incorporate into the code on the second line.
Should show some thing like this:
XXXXXXXXXXXX - 1 st line - Date and build code
3L55 8 8 XXXX - second line for an 8.8 with 3.55 Limited Slip
3L55 9 75 XXXX - second line for 9.75 with 3.55 Limited Slip
I show 3.73's only offered in the 8.8" rear. The 4.10s and 4.56s are in both sizes.
Hope that helps.
-Kerry
Not quite sure on the positive identifier (bolt #s and shape of cover), but the truck comes from the factory with the tag hanging off one of the bolts. It has the ring gear size incorporate into the code on the second line.
Should show some thing like this:
XXXXXXXXXXXX - 1 st line - Date and build code
3L55 8 8 XXXX - second line for an 8.8 with 3.55 Limited Slip
3L55 9 75 XXXX - second line for 9.75 with 3.55 Limited Slip
I show 3.73's only offered in the 8.8" rear. The 4.10s and 4.56s are in both sizes.
Hope that helps.
-Kerry
