Having some issues raising the rev limit on my 4t45e to 7000rpm from 6500. When it tries to shift into the next gear at WOT it just hangs up and wont shift. I used a calculator for gear ratio and tire size to determine the appropriate shift mph difference and came up with 3mpg on the 1-2 shift 6 mph on the 2-3 shift and 8mph on the 3-4 shift but it still hangs up. Does anyone have any insight into this?