my swap I used a painless harness, I had misread the instructions since it came with plugs for the 4l80 and 4l60. I hooked up the in to the out or something like that and it did like Allen said it shifted at 4 grand, I reread the instructions and got it hooked up right and it has been fine ever since. Well except when I go to second gear there is this squeeling sound I get from the rear area of the truck. well come to think of it it happens when I take off too, depending on the weight of my right shoe it varies in intensity

good luck.