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Richmond Gear 4900821 Ring and Pinion Gear Set 3.55 Ratio GM 10-Bolt

(Pontiac GTO 1964-72, Firebird 1967-72, Grand Prix 1964-72, Bonneville 1964-72, LeMans 1965-72, Catalina 1964-72, Tempest 1964-70 + 13 more models)

Part of: Richmond Gear Excel Differential Ring and Pinion Set

Other options in this family: Richmond Gear F9411 Richmond Gear F88410 Richmond Gear 4900391 Richmond Gear 12BC373T Richmond Gear 6903041

Manufacturer

Picture for manufacturer Richmond Gear

Part Number

4900821
4 reviews
Sale Price

$467.11

4 left at this price

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Usually delivered within 2 days

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Product Details

The Richmond Gear 4900821 is a high-quality ring and pinion gear set designed for GM 10-bolt rear differentials. This street gear set features a 3.55:1 gear ratio, providing an excellent balance between acceleration and fuel economy for daily driving applications.

Key Features:

  • 3.55:1 gear ratio optimized for street performance
  • Precision-manufactured from high-strength steel alloys
  • CNC machined for exact tolerances and proper gear contact
  • Heat-treated for maximum durability and wear resistance
  • Designed specifically for GM 10-bolt 8.5-inch rear axles
  • Includes both ring gear and pinion gear

Richmond Gear is known for producing premium quality drivetrain components with precise engineering and rigorous quality control. This gear set is ideal for street rods, muscle cars, and daily drivers looking to optimize their rear axle ratio. Professional installation with proper setup tools and new installation hardware is strongly recommended for optimal performance and longevity.

Products specifications

Fits

Pontiac GTO 1964-72, Firebird 1967-72, Grand Prix 1964-72, Bonneville 1964-72, LeMans 1965-72, Catalina 1964-72, Tempest 1964-70; Oldsmobile Cutlass Supreme 1967, Cutlass 1964-67, 442 1964-67, F85 1964-70, Jetstar 88 1965-66 + 9 more models

Calculator

Gear Ratio Calculator

Carrier Series

3

Cover Bolts

10

Installation Kit Included

No

Notes

3.36:1 or numerically higher carrier with 3/8 in. holes.

Pinion Gear Teeth

11

Pinion Shaft Diameter (in)

1.438 in.

Pinion Spline Count

27

Quantity

Sold as a set.

Ring and Pinion Ratio

3.55:1

Ring Gear Bolts

10

Ring Gear Diameter (in)

8.200 in.

Ring Gear Rotation

Standard

Ring Gear Teeth

39

Tool

Transmission Lookup

Ring Gear Tooth Quantity

39

Ring Gear Bolt Quantity

10

Pinion Gear Tooth Quantity

11

Ring and Pinion Gear Ratio

3.55

Differential Carrier Break

3.36 and Higher

Ring Gear Material

8620 Steel

Differential Case Design Type

GM 8.2 (BOP)

Cover Bolt Quantity

10

Ring Gear Diameter

8.2

Pinion Shaft Diameter

1.438

Prop 65

WARNING: Cancer - www.p65warnings.ca.gov

Position

Rear

good service, good merchandise.

Was linked here by Amazon. I found the absolute best price on the item I was looking for, I had a confirmation as soon as I ordered it, and shipping as prompt. I would definitely recommend these guys and will be shopping here myself in the future.

This is my first time ordering from them, but it certainly will not be my last. They have all the parts I need and the process and ship fast. Great company. And they're prices are awesome.

Order arrived fast. They were definetly the cheapest of all the online retailers.

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