High-horsepower 4L60E builds are everywhere these days thanks to the cutting-edge innovation and unrivaled quality of Sonnax shaft, clutch, servo and valve body upgrades. The newest addition to the company's robust lineup of performance parts is a heavy-duty, chromoly reaction shaft ideal for any modified vehicle running the 4L60E hard on the street or track. OE and aftermarket reaction shafts made from plain carbon steel often exhibit spline twist and fretting/wear in high-torque applications, especially when used in heavy vehicles. To eliminate these problems, the Sonnax shaft is made from a high-strength, chromoly alloy that guarantees the ultimate in performance and durability. In developing the shaft, Sonnax added not just strength, but ease of use. Its unique design, plus the bearings and shim included in the kit, allow quick assembly with any style input carrier. This includes all four- and five-pinion carriers found in the 700-R4/4L60, 4L60-E, 4L65-E, 4L70-E or 4L75-E, as well as the Sonnax 2.84 ratio, six-pinion carrier. The Sonnax heavy-duty reaction shaft kit (Part No. 74602-01K) is recommended for new performance builds or when pulling a transmission out for work. It's most critical for vehicles running above 400hp, fitting squarely within the popular Sonnax Level 3 build category designed for extreme applications. For information, call 800-843-2600, ext. 398 or visit www.sonnax.com. (Content courtesy of Sonnax)