1996 Z71 strange transmission problems

I have a 1996 Silverado that has 126k miles on it. I started having problems about a year ago with a real hard shift between 1st and 2nd. I thought I was losing a tranny but my local guy diagnosed it as a tps and replaced it. Problems ceased. I am now on my third tps and the problem is back. Tranny guy says its probably my ecm and could cost me a bundle. However, the problem has now taken on new charactistics. My truck now revs going from 2 to 3 and once in awhile I get the hard shift. Most of the time the tranny shifts fine and if I really want to get rid of the problem I unhook the battery and it goes away for several days. Could this be something else besides the tranny like the vss or the vpc or the main computer. Help would be appreciated.

ignition switches go bad in those cause all kinds of problems tranny dash problems gauges work funny.

in 1996 they had an issue with a ground wire you gotta get from the dealer