When it comes to Chevrolet rearends, information technology's the 12-bolt that seems to get all the accolades. Rightfully so, because when comparing the 10 and 12-bolt units, it'southward definitely the more than durable of the two. That's usually proven when used in high-performance, high-horsepower applications. But for all intents and purposes, the 10-bolt rearend is a great unit for a street/strip car, and can exist stout enough to handle even the occasional abuse delivered by use at the racetrack.

Finding a 12-commodities that is "affordable," is getting to be a about impossible endeavor. For that reason, many enthusiasts are because the ten-commodities. Simply, did you know at that place is more than 1 mode of 10-commodities rearend? One is the small, 7.v-inch, another is the 8.ii-inch, and even so two more are the 8.5 and eight.6-inch. If you're looking for a good.economical 10-bolt rearend to rebuild or install into your hot rod, you will demand to exist able to accurately place the different units and then you don't accidentally come dwelling house with a seven.5 or eight.2-inch differential.

The 8.v-inch 10-bolt rearend was used in cars and trucks over a wide range of years. Information technology first appeared in 1970 production cars as a corporate replacement for the 8.ii-inch x-commodities rearend. Information technology was used in dissimilar models by all GM divisions – with the exception of Cadillac. Since it was and then widely used, there is a better possibility of finding 1 of them at a relieve k than locating a 12-bolt. That is the impetus for why we decided to put this bandy meet/junkyard identification guide together. That manner, yous don't unknowingly spend money on something you really practice not want.

While the ten-bolt rearend's lineage tin be identified by the lawmaking stamps, which are usually on the passenger's side beam tube, in that location are literally hundreds of potential codes for the three different 10-bolt rearend housings. Since listing them all within this article is impossible, nosotros'll exist focusing only on visual identification.

7.5-Inch

Although the 7.5-inch x-bolt closely resembles the 8.v-inch housing, y'all tin positively identify the Chevy 7.5-inch rearend by measuring it. The oval-shaped cover measures 8 five/16 inches by x 9/16 inches. The distance betwixt the lesser center bolt in the cover and its next bolts is iii 1/4 inches. Inside, the ring-gear bolts are the same as the 8.5 corporate unit, but the pinion-shaft diameter measures 1.438 inches. Like most ten-bolts, the axles are held in place by C-clips on the inner end of the axles.

Many times, if you locate a 10-bolt rearend, it's unremarkably a 7.5-inch unit of measurement. These have been effectually since 1975, and were installed under cars, small-scale trucks, and vans up to the 2005 model year. If used in a daily driver or cruiser application, the 7.five-inch rearend should survive behind an engine with 350hp, if traction is express during spirited driving. If gummy tires are used, you'll chop-chop plow the 7.5-inch rear into a pile of unusable parts.

8.ii-Inch

There were an untold number of 8.2-inch axle assemblies built, and although information technology is only marginally stronger than the vii.5-inch rearend, it does have some aftermarket support. That being said, it is non recommended for use behind engines that make a serious amount of horsepower. Again, this would be okay in a daily driver or cruiser application, just if installed behind an engine with horsepower numbers climbing into the 400 range, you can plan on an eventual failure. While a carrier-begetting girdle is bachelor for the 8.2-inch rearend – and does requite some support to the housing – information technology doesn't provide a reliable and suitably strong solution.

The easiest way to identify the 8.2-inch rearend at a glance is by the shape of the housing and the spacing betwixt the lower bolts on the encompass. The eight.2-inch 10-bolt has a smooth, round, lower-example expanse (no cast-in protrusions), with an 11-inch cover that has a diagonal protrusion at the top. It besides uses a 10 5/viii-inch irregular-shaped comprehend. The pinion nut should as well measure ane 1/8 inches, if the OEM pinion nut is still in use.

Inside the eight.2-inch 10-bolt, the ring-gear bolts take ix/16-inch socket heads with iii/8-24 left-hand threads. The pinion diameter is ane.438 inches, and has 25 splines. Like all Chevy 10-bolts, the axles are retained by C-clips on the inner end of the axle shaft inside the carrier.

8.5-Inch

The 8.v-inch and viii.6-inch 10-bolt rears are stout and constructive differentials that can handle more power than either the 7.5 or 8.2-inch rears. While the eight.5-inch rearend was used on vehicles up to 1999, The 8.half-dozen-inch (8.625) was used on 2000 and later-year trucks. The easiest style to tell the difference is by looking at the brakes. All eight.half-dozen-inch rears have disc brakes, and 8.5-inch units have drum brakes.

The 8.5-inch ten-bolt rearend is hugely pop considering aftermarket carriers and gears are easily interchangeable. Originally, gear ratios ranged from 2.41 through 4.10. Yous will need to know that there are different series' of differentials (series two and three). With the exception of truck differentials with 30-spline axles, and those carrying two.41 and 2.73 gears (series two), the differentials will support all gear ratios without having to change carriers. The 8.five-inch 10-bolt also shares the same pinion shaft diameter every bit the more than expensive 12-bolt.

Most 8.5-inch 10-bolt rearends have ii extruded, bandage-in lugs on the bottom of the differential housing at the 5:00 and 7:00 positions. The covers on the 8.5-inch rearends are frequently 11 inches round with a bulge on the driver'due south side to accommodate the band gear. The distance between the lower heart bolt on the cover and either adjacent bolt is 3 3/4 inches. The OEM pinion nut is 1 i/four inches.

The 8.5-inch x-bolt rearends have ten iii/4-inch hex head bolts with 7/16-20-inch left-paw thread bolts that hold the band gear to the carrier. The pinion shaft diameter is 1.625 inches and will have either 28 or 30 splines. Like the viii.2-inch 10-bolt, the eight.v 10-bolts apply C-clips to retain the axles.

There is an anomaly to the "corporate" 8.v-inch axle assembly that was used in some 1971 and 1972 Buick, Oldsmobile, a few 1969 through 1972 Pontiac vehicles, also as the 1970 through 1972 Monte Carlo. Instead of using a C-clip to hold the beam in the housing, these axle assemblies use bolt-in axles, much like an 8.2 BOP rearend. Good luck finding one of these, nonetheless, as they are very popular among functioning enthusiasts.

Different Differentials

There are several differentials for the x-bolt rearend. That existence said, limited gear sets are offered for the carriers, specially if you lot plan to change gear ratios. Typically, 10-bolt differentials are specific to a series of gears. A Series 2 carrier will piece of work with 2.56 and higher gears (numerically lower) such as ii.41. These are considered highway gears that are proficient for acme speed, not for off-the-line functioning. The Series 3 carriers are good for use with two.73 and lower gears (numerically higher), and so iii.08 and 3.73 gears work well.

Unfortunately, unless you have the two units adjacent, it is nearly impossible to tell them apart. There is a difference, but you lot tin can't come across information technology unless you lot set both units on their side, and so measure the altitude from that surface to the face where the ring gear attaches.

Hopefully, this short list will exist plenty to help when you are scouring the bandy meets and salvage yards, and you will have an idea of what you're looking for, and how to place what you find.