4L60E 4L65E Stock Stall Torque Converter 300mm Lock-Up

This is a stock-stall lock-up torque converter for the GM 4L60E and 4L65E automatic, sized 300mm for the 1999-and-up transmissions that sit behind 4.8L, 5.3L, and 6.0L LS engines. It carries the 30-spline turbine hub and 300mm bolt pattern GM moved to on the late-98/99 LS trucks and SUVs, so it drops into a Vortec or LS-swap driveline without an adapter or a different flexplate.

Stock stall keeps the converter tight for street driving, towing, and daily use instead of letting engine rpm flare before the vehicle moves the way a high-stall unit does. This is the converter you want when you are rebuilding or replacing a 4L60E and the old converter is shuddering, has a dead lock-up clutch, or pumped debris into the transmission when the pump or clutches failed. Reusing a contaminated converter on a fresh rebuild is one of the fastest ways to send that rebuild right back to the bench, so it gets replaced with the unit.

Specs: 12.5 in outside diameter (300mm), 30-spline input shaft, 11 in bolt circle, three-pad flexplate mount, lock-up style, roughly 44 lb shipped. Prime it with ATF and turn it by hand to seat the pump drive before assembly, and confirm the converter is fully seated onto the pump before you draw the transmission up to the block.