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GM 10-Bolt with 8.5 Inch Ring Gear Rear End Differential Axle Cover

GM 10-Bolt with 8.5 Inch Ring Gear Rear End Differential Axle Cover

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Q & A

What's in the Box

Add some visual attitude to your rear axle with these chrome differential covers. They're stamped from heavy-gauge steel to ward off those pesky oil leaks, and chrome plated for long lasting good looks.

GM 10-Bolt 8.5 Inch Rearend Differential Cover


  • Full size and intermediate Chevy and GM cars 1971-1994
  • Axle types B, C, G, K and O.



  • 1971-1976 Chevrolet full-size cars
  • 1994-1996 Impala
  • 1971-1981 Buick full-size cars
  • 1973-1977 Buick Gran Sport
  • 1972-1977 Pontiac GTO and Le Mans
  • 1970-1981 Chevy Camaro and Z28
  • 1970-1981 Pontiac Firebird
  • 1971-1977 Olds Cutlass and F-85 and Pontiac Grand Prix
  • 1971-1979 Chevy II, Nova, Buick Skylark and Olds Omega
  • 1973-1977 Chevelle, Malibu and El Camino
  • 1971-1977 Pontiac Ventura and Phoenix
  • 1971-1981 Pontiac Bonneville
  • 1973-1977 Monte Carlo
  • 1973-1977 Buick Apollo, Regal and Century
  • 1980-1994 Chevy ½-ton and ¾-ton pickups
  • 1977-1994 GMC Jimmy and Chevy Blazer

You may also be interested in:

Lubrication Engineers SAE 140 Weight Gear Oil, 1 Gallon
(Part #91044140)

Whether you're running a stock flattie and rearend or hopped-up overhead and quick change, you need to run a good gear lube. Remember that your rearend was designed fifty plus years ago and needs all the help it can get. The biggest improvement you can give it is a lubricant that will allow the gears to survive the highway speeds that cars see today. L.E. gear oil is what we use in our 350 mph streamliner, that uses a V-8 quick change, without failure. The "red stuff" provides superior lubrication for long gear life. You can't win if you don't finish. We suggest 90 weight for the street and 140 weight for extreme uses.

  • Formulated using blends of high quality paraffinic and synthetic base fluids
  • Contains a highly shear stable tackiness
  • Unique blend of base fluids and thermally stable EP additives
  • Separates readily from water
  • Contains non-silicone defoaming additives
  • Contains no solids
  • Contains DUOLEC LE's proprietary dual acting liquid wear-reducing and extreme pressure additive

LE Gear Oil Data Sheet (PDF)

Rear Axle Breather
(Part #91045840)

This rear axle breather will stop lube from being flung out of rear axle housing. Allows "breathing" of rear axle assembly. 7/16"-20 thread. Polished!

Install with thread sealant or Teflon tape. Can be used on various applications with appropriate plumbing components.

GM 10 Bolt Ring and Pinion Instal Kit, 8.5 R&P, 30 Spline
(Part #919831021)
                        Everything you need for a complete ring and pinion installation job. 

Kit Includes:

  • cover gasket
  • crush sleeve
  • marking compound and brush
  • pinion and carrier bearings
  • pinion nut and washer
  • pinion seal
  • thread locking compound
  • sealer

Note: Pinion-depth shims are not included. 

1970-96 GM 10 Bolt 8 1/2 Inch Ring and Pinion
(Part #91910)

Many ratios to choose from.

  • 8.50" diameter ring gear
  • 1.625" diameter pinion
  • 10 ring gear bolts
  • 10 cover bolts
  • 30 pinion splines
  • Uses LH thread ring gear bolts - 7/16"-20

Note: When replacing a stock 2.56 (or numerically lower) ratio, the carrier must also be replaced with a 2.73 or higher ratio's carrier to compensate for the difference in ring gear thickness.

Finned Pol Alum Rearend Differential Cover, GM 8-1/2 Inch 10 Bolt
(Part #9115078)
                        These polished aluminum rearend gear covers feature a classic finned design and are made to fit GM 10 bolt housings with an 8-1/2" ring gear.
  • Chevy/GM polished aluminum rear differential cover with 10 bolt pattern
  • Fits Chevy/GM 10 bolt rear ends with 8-1/2" ring gear
  • Includes bolts and drain plug
GM TH350/TH400 Oil Pan Bolt Kit
(Part #91303806)
                        Chrome bolt set for TH-350 and TH-400 automatic transmission oil pans. 
8.2/8.5 GM Differential Gaskets
(Part #91069857)
                        - Pressed composite
- Fits GM cover 550-3783 & 550-3789
- 10 bolt GM 8.2 & 8.5 differentials