Lower stall converter yes, I pull a trailer 5 days a week and suncoast took care of the rest. She pulls nicely. One problem, going to call them tomorrow but when i shift from reverse or drive into park, I hear a little bit of a clunk clatter from like it not releasing completely cause of the driveshaft maybe? I also wonder if i could lower the idle rpm or was i even supposed to adjust the idle on 24valves as ive heard different stories from different people specifically to do with the accelerator pedal positioner or some crap. Any body got any clues, however when you change from drive to neutral then to park you do not hear the noise at all.