All trucks with 3.08 factory ratios (5.3 only) and 3.21 factory ratios (6.2 only) require a ring gear spacer in order to swap to any other ratio ring & pinion and retain the factory carrier. Part# GM9.5B-RG-SPACER

If switching to the Detroit Truetrac Posi or Yukon Duragrip, this is the equivalent to the 3.08 and 3.21 carriers and the afore mentioned ring gear spacer must be purchased in conjunction with either carrier choice. Our preference for these trucks is the Truetrac option.

Ratios available direct bolt in 5.3 Trucks:

3.73 - Yukon aftermarket gear, 3.08 requires ring gear spacer

4.10 - AAM Original Equipment Gear, 3.08 requires ring gear spacer

4.56 - Yukon aftermarket gear, 3.08 requires ring gear spacer

4.88 - Yukon aftermarket gear, 3.08 requires ring gear spacer

Ratios available with conversion parts 5.3 Trucks:

5.13 - Yukon aftermarket gear, requires conversion pinion yoke and seal, 3.08 OK, 3.42 & Up requires new carrier (IE Detroit Truetrac)

5.38 - Yukon aftermarket gear, requires conversion pinion yoke and seal, 3.08 OK, 3.42 & Up requires new carrier (IE Detroit Truetrac)

Ratios available direct bolt in 6.2 Trucks:

3.42 - AAM Original Equipment Gear, 3.21 requires ring gear spacer

3.73 - AAM Original Equipment Gear, 3.21 requires ring gear spacer

Ratios available with conversion parts 6.2 Trucks:

4.10 - AAM Original Equipment Gear, requires conversion bearing kit

4.56 - Yukon aftermarket gear, requires conversion bearing kit

4.88 - Yukon aftermarket gear, requires conversion bearing kit

Technical Notes:

AAM Original Equipment Gears come with crush sleeve, pinion nut and pinion seal. These are the quietest gears available.

Aftermarket gears are just the ring & pinion, no other parts.

GM9.5B-RG-SPACER - with the ring gear spacer you must take .020 out of the driver side shims. If using this spacer you need to purchase two carrier shim kits (SKCSS-GM9.5)

In some cases we have seen the need to space out the differential cover or replace the differential cover with an aftermarket cover if so desired. Most likely to happen with 5.13 and 5.38 ratios.

9.5 12 Bolt Specs:

Pinion Shim: .023 under the bearing

Carrier Shim - Drivers side: .242 Passenger side: .227 (No side adjuster like old GM9.5)

33 Spline axles G80 Gov Lock is still a factory installed option

OE Deck Height on Carrier 2.610

9.76 12 Bolt Specs:

Pinion Shim: .150 under the bearing

Carrier Shim - Drivers side: .242 Passenger side: .227 (No side adjuster like old GM9.5)

33 Spline axles G80 Gov Lock is still a factory installed option

OE Deck Height on Carrier 2.610

2014 and newer Chevy 1500 Regear Options Front - 5.3/6.2: 3.08/3.21 factory ratios require new front carrier, part# GM8.25IFS-CASE. Stock spider gears can be re-used in new carrier.