In the early sixties, American cars with four speed transmissions often used the same make be it GM, Ford, AMC or MoPar. The Borg-Warner T-10 was the transmission of choice for the auto industry. It debuted in 1957 in the Chevrolet Corvette and eventually saw use in full size Chevrolets, Buicks, Oldsmobiles, Pontiacs, early Fairlanes and Mustangs. The T-10 is based on the earlier three-speed transmission called the T-85. A close look at the layout inside reveals the T-10 is just the three speed with the reverse gear tucked into the extension housing to make room for the fourth gear. The main case was aluminum on Corvettes. Other Chevrolet cars used cast iron cases until 1962. The T-10 was considered a heavy-duty transmission back then and was issued with the hi-performance engines of the day. 283 fuelies, 348's, Pontiac 389's were the type of mills using the T-10s. MoPar used them for 1963 until their own transmission was ready. Competition ended the T-10's domination. Muncie, Saginaw and New Process all developed transmissions capable of handling larger engines and torque requirements. By 1965, widespread use of the T-10 was over. However, the story didn't end there. Drag strip racing uncovered the flaws of the original design and research efforts by many racers developed new tricks to improve the basic design of the T-10, making it a competitive four speed. The result of this R&D was the Super T-10 released in late 1969. This revised transmission had an iron case instead of aluminum. The gear sets were larger than the originals for added strength yet were smaller than either Muncie or New Process gears. The gears were made from high 9310-nickel alloy and were a coarse cut for better load capacity. You had more ratios to choose from as well.

The Super T-10 was a much-needed improvement. Development continued with more changes added to production transmissions. The racing and aftermarket line of Borg-Warner was called Power Brute. This was where you could order the new gear ratios and trick pieces such as heavy-duty synchro sleeves. The GM versions of these transmissions were 92 pounds while full-size Fords weighed in at 101 pounds. Ford used 3 versions of the T-10 in their cars. The light bodied cars use a 2.73:1 low gear, 2.06:1 second and 1.62:1 third gear ratio. As in all other applications, the fourth gear is direct drive. Big block Galaxies and Shelby Cobras use a 2.36 first gear, 1.62 second and 1.20 third gears. The third version used a 2.36 first gear, 1.76 second gear and 1.41 third gears. MoPar in 1963 uses T-10s with 2 different gear sets. The standard set has a 2.54 first gear, 1.89 second and 1.51 third gear. The other was a close ratio set with 2.20 first, 1.64 second and 1.31 third gears. Modifying the T-10 for better performance is worthwhile. The design is very good and shifting is smoother than in an M-22 or an 833 New Process. The only caveat is when it comes to heavy racing use. The aluminum case is fragile and in early T-10s, the gearshafts are prone to flexing under high loads. When it comes to serious drag racing, many would switch to a Muncie or other truly rugged transmission. Only a 1975 or later Super T-10 would be suitable for serious racing. This is a second revision model to be covered in detail later.

A word about using Super T-10 gearshafts inside an aluminum T-10 case; don't bother. You only save 30 pounds and trade away lots of reliability. Machine work is involved in fitting a later model shaft. Once you get them inside, you have high nickel alloy shafts crashing against an aluminum housing. The dense shafts will crack your trans shift cover , then your case in that order. However, I would consider using the Ford shifter arms and shifter shafts from a Ford T-10. They use 3/8-inch studs, which is thicker than the 5/16 GM shafts. If your T-10 still has the older bearings with the non-grooved sleeve, go for an upgrade. Borg-Warner has employed the heavy-duty bearings in production trans since 1975. Power Brute made heavy-duty bearings available since 1972 for the aftermarket. I have found these bearings in production units as well. In GM cars, using a 27-spline mainshaft absorbs the stress of high-rpm launches better than Chevy mainshafts. The 27-spline mainshafts can be found in Buick cars using the T-10. Examine the blocking ring and its corresponding gear and check for proper clearance between gear and ring. You want at least 0.50-inch. The two parts should face evenly without wobbling. Use another blocking ring if your doesn't seat firmly. In 1975, the Super T-10 was revised a second time. This model incorporated many of the above mentioned changes suggested for the T-10s plus a few great ideas that make this the ultimate model to use for worry-free motoring. AMC was the only company still using the T-10 by 1970. The second design is 50% stronger than the 1970 design. The 1975 case is also 10 pounds lighter. The main case is nodular iron with the aluminum extension. The gears are wider and use a coarse cut for better load capacity. The gears are nickel chrome moly SAE 8620. The first gear is sleeved for better oiling and the cluster countershaft is 1-inch in diameter. Four ratios were available with 2 close and 2 wide ratios. GM cars benefited from these mods as Warner tries to compete against the Muncie units.