★★★★★ Exactly as described
Sarah M · Dunedin · Example review Price was the price, no surprises. Return pickup was already booked which made life easy.
Low stock, 2 left
GM 8.4 Ring and Pinion 3.73 Ratio 55-64 Chevrolet Passenger
This GM 8.4 3.73 Ring and Pinion is a Revolution Gear replacement set built for 1955 to 1964 Chevrolet passenger cars fitted with the 8.4″ drop-out differential head. Revolution Gear manufactures it from 8620 steel and precision.
$795 incl GST
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Fitting availableFitted in store at Gearhead Diffs, Sydenham
12 months or 20,000 kmOn parts we supply and fit
Fitment
SuitsGM 8.4 Ring and Pinion 3.73 Ratio 55-64 Chevrolet PassengerMakeChevroletModelImpala 8.4" Drop outPositionRearRatio3.73BrandRevolution GearSKUGS-GM55P-373
Not sure it suits your vehicle? Send us your rego and we will confirm before you order.
Warranty and delivery
All work and parts supplied by Gearhead Diffs are covered for 12 months or 20,000 km, whichever comes first, provided the vehicle is serviced to schedule, filled with the correct spec Red Line oil and not misused.
Shipped NZ wide by courier. Overnight to most South Island addresses, one to two days to the North Island, rural delivery can add a day. Freight is calculated at checkout, or free when it travels in the box with an exchange diff.
Description
GM 8.4 3.73 Ring and Pinion (55-64 Chevrolet Passenger, Drop-Out Diff)
This GM 8.4 3.73 Ring and Pinion is a Revolution Gear replacement set built for 1955 to 1964 Chevrolet passenger cars fitted with the 8.4″ drop-out differential head. Revolution Gear manufactures it from 8620 steel and precision heat-treats it to OEM specifications, so it holds up to the demands of daily driving, off-roading, and racing alike.
Specifications
- Material: 8620 steel
- Heat Treatment: Precision heat-treated to OEM specifications
- Lapping: Double lapped (triple lapped on some sets)
- Differential: GM 8.4 inch drop-out (55-64 Chevrolet passenger)
- Ratio: 3.73
In particular, 8620 steel is a proven choice for ring and pinion gears because it balances strength with the toughness needed to resist chipping and wear. As a result, the gears hold their shape and tolerances under load after heat treatment. Additionally, Revolution Gear’s extra lapping step extends the working life of the gear set, which standard aftermarket alternatives often skip entirely.
8.4 3.73 Ring and Pinion Fitment
This set suits Chevrolet passenger cars built between 1955 and 1964 that use the 8.4″ drop-out differential head. The 3.73 ratio suits drivers who want a balance between off-the-line acceleration and comfortable highway cruising. However, GM used several different housings across this era. So, always confirm your differential’s exact specifications before ordering.
Why Choose Revolution Gear
Revolution Gear and Axle has built its reputation over more than a decade of street, off-road, and race use. In particular, enthusiasts trust the brand because it delivers consistent quality across a wide range of applications, not just classic GM passenger cars. As a result, that track record gives you confidence. Overall, this gear set will perform as well in your project as it has in thousands of others already on the road.
Not sure if this ring and pinion set matches your differential? Get in touch and we’ll help you confirm fitment before you order. For more on Revolution Gear’s GM ring and pinion range, see their official product category page.
Reviews
No reviews on this product yet. Bought one? We would like to hear how it went. Write a review Bought this? You'll get a review link by email three weeks after it ships. Only customers who have bought the product can review it. Example reviews These three are examples to show the layout. Real reviews from verified buyers replace them as they come in.
★★★★★ We fit these for customers every month
Workshop customer · Christchurch · Example review Order before 2pm, on the bench next morning. Preload sorted so we do not see them back. Saves us a hoist for a week every time.
★★★★★ Sorted the clunk
Dave P · Nelson · Example review Rang the team first to check it was the right one for my rego. It was. Fitted by my local mechanic, no more clunk on take off.
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