RPM slow runaway in 2nd gear

[2xls1]

That explains why I cant find another 03 Silverado cal to compare your bin to. The most important thing I've found on swaps using blue/green PCMs is knowing what parts you have and not mixing up different year ETC throttle bodies/tac modules/pedals/year calibrations. Assuming this is still an ETC setup.

[ColPaul]

It is an ETC setup. I believe the TAC, pedal, etc. all came from the '03 donor Silverado. Thanks for the warning. We will try to keep everything but the OS an '03.