I see lots of threads on here about swapping from the 4l60E to the 4L80E. I stumbled across this today while looking at torque converters. Sounds like this might simplify things quite a bit. If anybody has infor on this or tries it out, it would great to hear how it works!
http://www.4l60-e.com/#4L60E to 4L80E
http://www.4l60-e.com/#4L60E to 4L80E