The competitive world of drag racing is constantly changing. While the GM Powerglide remains a popular transmission choice due to its proven durability, its 2-speed configuration sometimes leaves something to be desired due to the RPM drop between gears. Recognizing this dilemma, the engineers at TCI designed a TH400 transmission that is capable of handling the same elevated horsepower levels as the Powerglide but with the advantages of a 3-speed configuration. Beyond the built-in gearing advantages, TCI also incorporated a "clean neutral" feature after high gear and a Pro Tree Trans-Brake that enables quicker, more consistent launches.

The PRO-X TH400 utilizes premium component upgrades that reduce reciprocating weight while also providing bulletproof durability that was once thought impossible in a TH400. Upgrade components include five friction clutches and five Kolene steels in the intermediate pack, a 7075-T6 billet aluminum rotating assembly, as well as a main shaft and input shaft made from a hybrid aerospace metal alloy. The GM TH400 pump comes with polymer dry film coated gears and a staked stator support shaft. These upgraded components reduce reciprocating weight by up to 16 pounds and additional CNC-machining to the GM TH400 case allows the use of spiral locks to support components around the center area for increased strength and concentricity.

Another impressive feature of the PRO-X TH400 is the "Clean Neutral" Pro Tree Quick Release Valve Body, which provides the quickest reaction times available and promotes safety by enabling a shift into a second neutral after crossing the finish line. This unique transmission is truly the best 3-speed unit available for the 1500-3000+ HP applications, from Hot Street to Outlaw 10.5 classes.