i JUST finished mine as well, 4l60e with the transgo hd2 and i have the same problem,1st feels like second. i only drove it maybe a mile, I havnt installed anything for the servo that came with the kit but i wanted to make sure everything else was good, sopposably it has a vette servo already installed , i will remove it this afternoon when it stops raining but if there is no vette servo would it cause this problem also?? like i said it feels like second or the ebrake is dragging , not trying to thread jack or anything just having the same issue.
06 silverado crew cab 4.8L
STS Kit W/turbonetics BB 60-1 .81AR T4 and intercooler 10psi
Nelson custom tune
built 4L60E-hopefully it lasts
2500 stall-Hughes converters
42LB injectors
3.5 Magnaflow exhuast
6inch lift on 35x12.50s