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Richmond Gear 79-0074-1 Pro Gear Ring and Pinion GM 8.875" 12-Bolt 4.33 Ratio

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

Part of: Richmond Gear PRO Gear Differential Ring and Pinion Sets

Other options in this family: Richmond Gear 7900171 Richmond Gear 7900801 Richmond Gear 7900431 Richmond Gear 7900451 Richmond Gear 7900791

Manufacturer

Picture for manufacturer Richmond Gear

Part Number

7900741
5 reviews
Sale Price

$582.36

2 left at this price

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Product Details

The Richmond Gear 79-0074-1 is a Pro Gear differential ring and pinion set engineered for the GM 8.875" 12-bolt passenger car axle. Featuring a 4.33:1 gear ratio with a 39-tooth ring gear and 9-tooth pinion, this set is purpose-built for high-demand racing applications where hard launches and extreme heat cycling are routine.

Key Features:

  • Application: GM 8.875" (12-bolt) passenger car differential, Carrier Series 4 (3.90 and higher)
  • Gear Ratio: 4.33:1 (39 ring teeth / 9 pinion teeth)
  • Material: 9310 steel alloy — softer and more malleable for superior breakage resistance under racing conditions
  • Rotating Weight Reduction: Up to 6 lbs. of rotating weight reduction compared to standard gears
  • Pinion Threads: Ground to gauge quality for trouble-free installation
  • Heat Treatment: Specialty heat treatment process for enhanced strength and durability
  • Pinion Shaft Diameter: 1.625 in.
  • Pinion Spline Count: 30
  • Ring Gear Bolt Count: 12
  • Carrier Break: 3.90 and higher
  • Sold as a complete ring and pinion set (installation kit not included)

Richmond Gear Pro Gear ring and pinion sets are manufactured using computer-controlled processes from the foundry through gear cutting — held to 1/1000th of an inch precision — and through final heat treatment. The result is a consistently strong gear set trusted by professional racers at events including the Daytona 500 and NHRA U.S. Nationals. Cross-reference part numbers include Motive Gear G988430 and Richmond Gear 82-0514-1.

Products specifications

Fits

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

Calculator

Gear Ratio Calculator

Carrier Series

4

Cover Bolts

12

Installation Kit Included

No

Notes

3.90:1 or numerically higher ratio carrier.

Pinion Gear Teeth

9

Pinion Shaft Diameter (in)

1.625 in.

Pinion Spline Count

30

Quantity

Sold as a set.

Ring and Pinion Ratio

4.33:1

Ring Gear Bolts

12

Ring Gear Diameter (in)

8.875 in.

Ring Gear Rotation

Standard

Ring Gear Teeth

39

Tool

Transmission Lookup

Ring Gear Diameter

8.875

Cover Bolt Quantity

12

Differential Case Design Type

GM 8.875 Car

Ring Gear Bolt Quantity

12

Ring and Pinion Gear Ratio

4.33

Pinion Shaft Diameter

1.625

Ring Gear Tooth Quantity

39

Differential Carrier Break

3.90 and Higher

Ring Gear Material

9310 Steel

Pinion Gear Tooth Quantity

9

Position

Rear

Prop 65

WARNING: Cancer - www.p65warnings.ca.gov

Very simple and painless

So far so good

Great transaction at a great price.

Super easy + best price on the web. Very pleased am I.

I am extremely satisfied with Autoplicity in terms of service, price, and shipping. I was shopping for a set of N-FAB step bars for my truck and was ready to purchase from Amazon when I decided to look around to see if there were better prices. I stumbled upon Autoplicity and was surprised to see their price on the bars. I checked with their online chat customer service to confirm that they would fit my truck and that the price was for a pair of the bars and not just one. (That's how low the price was!). I then placed my order and the bars arrived at my doorstep 3 days later! Autoplicity gets an A+ in my book and I'll definitely be coming back.

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