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Richmond Gear 4900391 Ring and Pinion Set 3.73 Ratio GM 12-Bolt

(Chevrolet Camaro 1967-72, Impala 1965-72, Malibu 1965-67, Chevelle 1964-73, Caprice 1966-72, El Camino 1965-73, Monte Carlo 1970-72 + 42 more models)

Part of: Richmond Gear Excel Differential Ring and Pinion Set

Other options in this family: Richmond Gear F9411 Richmond Gear 12BC373T Richmond Gear 6903041 Richmond Gear 7900601 Richmond Gear 6901611

Manufacturer

Picture for manufacturer Richmond Gear

Part Number

4900391
12 reviews
Sale Price

$306.26

In Stock (10)

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Usually delivered within 2 days

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Product Details

The Richmond Gear 4900391 is a high-performance ring and pinion gear set engineered for GM 8.875-inch (12-bolt) passenger car differentials. This precision-machined gear set features a 3.73:1 gear ratio that optimizes acceleration and power delivery for street performance and muscle car applications.

Key Specifications:

  • Gear Ratio: 3.73:1 (41 ring gear teeth / 11 pinion gear teeth)
  • Differential Design: GM 8.875-inch 12-bolt passenger car
  • Carrier Series: 3 Series (requires 3.07 to 3.73 ratio carrier)
  • Pinion Spline Count: 30 splines
  • Ring Gear Diameter: 8.875 inches
  • Pinion Shaft Diameter: 1.625 inches
  • Material: Premium 8620 steel construction
  • Ring Gear Bolts: 12-bolt configuration

Performance Features:

  • Precision-ground pinion threads for trouble-free installation
  • Special heat treatment process for enhanced strength and durability
  • Quiet operation with smooth tooth engagement
  • Designed for high-performance street and racing applications
  • Backed by Richmond's proven racing heritage from Daytona 500 to U.S. Nationals

What's Included: Ring and pinion gear set only. Installation kit, bearings, shims, seals, and carrier not included—must be purchased separately.

Richmond Gear has been the trusted choice of professional racers and performance enthusiasts for over 80 years. Each gear set is manufactured using state-of-the-art processes and undergoes rigorous quality control to ensure proper fitment, acceptable tolerances, and maximum strength. This gear set is ideal for classic GM muscle cars and performance builds requiring reliable power transmission and improved acceleration.

Products specifications

Fits

Chevrolet Camaro 1967-72, Impala 1965-72, Malibu 1965-67, Chevelle 1964-73, Caprice 1966-72, El Camino 1965-73, Monte Carlo 1970-72, Nova 1964-67, 1969-72, Chevy II 1964-68, Bel Air 1965-70; Pontiac GTO 1965-72, Firebird 1967-72 + 37 more models

Calculator

Gear Ratio Calculator

Carrier Series

3

Cover Bolts

12

Installation Kit Included

No

Pinion Gear Teeth

11

Pinion Shaft Diameter (in)

1.625 in.

Pinion Spline Count

30

Quantity

Sold as a set.

Ring and Pinion Ratio

3.73:1

Ring Gear Bolts

12

Ring Gear Diameter (in)

8.875 in.

Ring Gear Rotation

Standard

Ring Gear Teeth

41

Tool

Transmission Lookup

Pinion Gear Tooth Quantity

11

Ring Gear Bolt Quantity

12

Ring Gear Tooth Quantity

41

Differential Carrier Break

3.07 to 3.73

Ring Gear Material

8620 Steel

Cover Bolt Quantity

12

Ring Gear Diameter

8.875

Ring and Pinion Gear Ratio

3.73

Differential Case Design Type

GM 8.875 Car

Pinion Shaft Diameter

1.625

Prop 65

WARNING: Cancer - www.p65warnings.ca.gov

Position

Rear

Easy to use

.

Fast and easy. Thank you so much.

fast , best price online, thanks

Easy.

found exactly what l was looking for in a hurry!

Great Price for the struts i ordered!

Excellent price on the product and shipping! Ordered on Thursday night (after they closed) and they were shipped out Monday!

Good price and easy transaction... slow to ship though.

Easy to use site with competitive pricing.

Great prices, better than any competitors and shipped fast. You do pay for shipping, but the discount on the merchandise makes up for that! So far would purchase from them again!

Fast shipping, Great prices. After ordering,they sent out an email stating some items ordered may ship from the manufacturer. So, I was thinking item may take a few weeks to get. The next day I recieved email with tracking numbers saying item has shipped. So I was think ups ground 5 days maybe. I check on tracking numbers and items was out on truck for deliver. Nice! Ordered on Weekend got item on Tuesday.

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