So what specifically do you have to change to swap the 4l60 for 4l80 with the 4x4 driveline? I'm at 210k and I'm starting to feel things going wrong in the trans, it doesn't help it's freezing. But since I knew it was going to happen eventually, I need to start planning. The truck doesn't get worked hard, pulls a boat and a small trailer occasionally, but if I'm going to have to mess with it, might as well see if I can get the upgrade.

And how hard would it be to have working turnsignals on the mirrors? I'm wondering if the bcm will just notice that all of a sudden it's got mirrors with signals in them or do you have to turn it on in the bcm somehow?

Right now I've got a stock trans cooler, anyone got any suggestions to source larger aftermarket ones?