Quick update... While the guys at Sprintex worked hard and sent several tunes to try to get it straight, I'm done. The cold weather operation was never quite right, but the worst part was the transmission. That's really an issue with the Diablosport tuner rather than the Sprintex SC. My Jeep is currently in the capable hands of Robbie at MoTech getting an LS3 and 6L80E. He's also replacing the driveshafts with heavy duty units. All the original equipment options, such as cruise control, remote start, stability control, traction control, and of course the dash, will work as usual. The only difference will be the smooth linear power of a 6.2L V8 and an efficient 6 speed automatic! If anyone has interest in how this goes, I can start a separate thread once I get the jeep back.