Michael Accardi 
Designed specifically to support the new ZZ632 Big-Block motor, the Chevrolet Performance SuperMatic 4L75-R is the highest capacity transmission available via the 4L60/4L70 transmission architecture. The new gearbox is more than capable of handling 1,004 naturally aspirated horsepower, and 876 lb-ft of torque, without turning to glass. And it made its debut at the 2021 SEMA Show.
Chevrolet Performance 4L74-R: Designed To Handle Over 1,000 Horsepower
Significantly, the new 4L75-R is actually smaller and lighter than the less capable SuperMatic 4L85-E transmission. A quick look at the Chevrolet Performance Catalog sheds a bit more light on the technical details of the new gearbox. Most impressive.
Compared to the rest of the 4L60/4L70-series automatic transmission family the 4L75-R gains a stronger 6-pinion input carrier and sun gear, heavier duty output shaft, higher-capacity servo, and specific valve calibration. Other improvements include updated accumulators, overrun clutch, reaction shell, boost sleeve, and an upgraded thrust bearing to support greater torque capacity. Gear ratio’s are listed as: 1st: 3.06, 2nd: 1.62, 3rd: 1.00, 4th: 0.70, which are identical to those listed for the less capable 4L75-E.
The transmission doesn’t include a torque convertor and will require some research into which convertor will best suit your application. Funny enough, despite being designed to support the ZZ632 engine, Chevy explicitly states in the catalog that the flexplate included with the installation kit is not rated for the output of the 10.4-liter Big-Block.
But just because the 4L75-R was designed to support the new 10.4L ZZ632 Big Block V8 program doesn’t mean it’s tied exclusively to that engine. There’s a subsequent section of the catalog dedicated to selecting the right installation kit, bell housing, and torque convertor.
For those of you who don’t know, the 4L75-R transmission is a derivative of GM’s long-running workhorse, the 4L60-series. That transmission was on duty in the Corvette, Camaro, Silverado, Tahoe, and Suburban, not to mention its use in other GM products like the GMC Sierra and Yukon.
The transmission is due to become available during the first-quarter of Q1 next year. But never mind that, we’re sitting here wondering just what the first application of the 4L75-R is going to look like. Check back for pricing.
