Perhaps you can find a torque converter with a lower stall speed?
One is made for the 42RLE's predecessor, the 42LE, but, because of case changes, I can't say it will or will not fit.
If it does fit, you'll lose the 42RLE torque converter's ability to dampen harsh shifts - controlled through the TCM (transmission control module). Prolly throw codes, too, maybe even put you in limp mode.
Switchable lockup kits are available for many more common automatics and I think it could be done with the 42RLE, the question is where. At the solenoid or at the TCM? One route to pursue would be fooling the 4th gear pressure sensor...no idea how to do that.
Last edited by funfred; 02-07-2017 at 06:44 PM.