Bill Smith
Founder, 1929-2014
Speedy Bill
Since 1952
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America's Oldest Speed Shop ®


1970-96 GM 10 Bolt 8 1/2 Inch Ring and Pinion

SAME DAY SHIPPING! Most orders ship within 24 hours.

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Inside thickness of ring gear is 1.7"
1970-96 GM 10 Bolt 8 1/2 Inch Ring and Pinion

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Q & A

What's in the Box

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.


  • Buick Full Size 1977-1996
  • Buick Electra 1976-1978
  • Regal 1973-1977
  • Century 1973-1977
  • Skylark, GS 1971-1975
  • Skylark, GS 1977-1979
  • Chevy Full Size Car 1971-1996
  • Chevy II 1971-1979
  • Nova 1971-1979
  • Camaro 1971-1981
  • Firebird TA 1971-1981
  • Cutlass 1971-1977
  • El Camino 1971-1977
  • Monte Carlo 1971-1977
  • Impala 1991-1996
  • Olds Full Size 1971-1989
  • Pontiac  Full Size 1971-1989
  • Grand Prix 1971-1977
  • Lemans 1971-1977
  • GTO 1971-1977
  • Ventura 1971-1977



Note: Circle track racing applications require a minimum of 4 qts. of rear end lube. Using less than this amount will lead to immediate pinion bearing failure.

You may also be interested in:

DVD - Richmond Gear Installation Instruction
(Part #2379334)
                        Shows you how to properly install ring and pinion gear sets. Packed with information for correct installation procedures. 
Cross Pin GM 10 Bolt 8 1/2 Inch Ring & Pinion
(Part #919800272)
                        Special 4130 Chromoly cross pin required for ratios of 5.38 or higher. 
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. 

Lubrication Engineers SAE 90 Weight Gear Oil, 1 Gallon
(Part #91044090)
                        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 Performance Data Sheet (PDF)

LE Gear Oil Safety Data Sheet  (PDF)