Thanks for your reply "Tenn TechMan". That is the info that I was looking for. I will now proceed with programming ECM. This tune is suppose to add another 25HP at the wheels (which is nice) and adjusts the shift patterns of the transmission. The shift pattern change is what I needed. Again thanks for your reply, Jimbo in Calgary
P.S. I might never have tried improving the tune on my ECM, but for the fact that a fellow I talked to when out camping told me about the tuner he hooked up to his new chev 3/4 ton pulling a 25 ' trailer. Increased MPG and HP. He has it installed on his other trucks too and was very happy with it.