USA Standard Ring & Pinion Gear Set For GM 8.2in in a 3.55 Ratio
A Chevelle, Nova, Impala or El Camino that still has its 8.2 in. ten-bolt rear often wears an open-road ratio like 2.56 or 3.08 from the factory, or a set of gears that has whined for decades. The USA Standard Gear ZG GM8.2-355 is a new 3.55 ring and pinion for the Chevrolet 8.2 ten-bolt. 3.55 is the classic street compromise: much quicker off the line than a highway ratio, still livable at cruise with a three-speed automatic, and a good match for an overdrive swap.
The pinion gear on the end of the driveshaft yoke turns the 8.20 in. ring gear on the differential carrier. In a 3.55 set the pinion turns 3.55 times for each axle turn. The Chevy 8.2 uses a 25-spline pinion with a crush sleeve, C-clip axles held by the spider gear cross pin, and 10 ring gear bolts with left-hand threads. Gear sets are specific to this axle: the Buick, Olds and Pontiac 8.2 and the later corporate 8.5 share the ring size or name but not the gear set.
Several GM ten-bolts look alike, so check before you order. The Chevy 8.2 has a smooth, rounded lower housing with no square lugs at the bottom, while the 8.5 has two square casting lugs. With the cover off, the 8.2 cross pin bolt takes a 1/2 in. wrench, the ring gear bolt heads are 9/16 in. with left-hand threads, and the axles use C-clips. If the axles bolt in through a retainer plate, you have the Buick, Olds and Pontiac 8.2, which takes a different set and the BOP 8.2 overhaul kit. Count the teeth on the old ring and pinion to find your current ratio.
This set is cataloged for the GM 8.2 in. rear in the 1964-1972 Chevrolet Bel Air, Biscayne, Impala and El Camino, 1964-1972 Chevelle, 1966-1971 Caprice, 1967-1970 Camaro, 1964-1968 Chevy II, 1969-1972 Nova and 1970-1972 Monte Carlo. GM switched many of these cars to the 8.5 around 1970-1971, and many old cars have had rear ends swapped, so the year alone does not prove which axle you have. Use the identification points above, or send us your year, model and VIN and we will help check it. More axle parts are in our hard parts collection.
| Brand | Yukon Gear & Axle |
| Part number | ZG GM8.2-355 |
| Fits | USA Standard Ring & Pinion Gear Set For GM 8.2in in a 3.55 Ratio |
| Type | Final Drive Gears |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The BOP 8.2 uses bolt-in axles and different gears. This set is for the Chevrolet 8.2 with C-clip axles.
No. The 8.5 uses a larger ring gear and a different pinion. Check for square casting lugs at the bottom of the housing; those mean 8.5.
3.55 suits a street car with a three-speed automatic or four-speed manual on 26-27 inch tires, and it pairs well with an overdrive transmission swap. Run your tire height and cruising speed through a gear ratio calculator first.
New carrier and pinion bearings, a pinion seal, shims, a crush sleeve and ring gear bolts. The Yukon 1964-72 GM 8.2 master overhaul kit includes all of them.
Drive gently with no hard launches for the first few hundred miles, avoid long high-speed runs that heat the axle, then drain and refill the gear oil.
