If you're referring to it being under WOT when shifting short, then yes it's commanding the 1-2 shift at 26MPH. You probally need to raise that.

 

Thats what i figured, even when i drop it down to first, it still shifts to 2nd at about 26mph, hadnt paud attention to the speed until now... Was more concerned with consistent 1-2 at 3500rpm.... Im gonna play with it tonight, hopefully... Thinking ill bump it up to 40 or 42 and see what happens, wish i had the stock file to see what it was originally set at..

 

try 35 first.

 

Looks like 25 was a factory number.

 

Thats weird the factory tune in the yukon had 1-2 at 40....

 

I looked at a base 5.3L file from 99 and that's what it showed. 25MPH

Shows 4.10's as the gear ratio.

Tires and gears will also play a role.

 

Just looked, Mine was changed and set to 41 in my old 2000 truck.

25 was the stock value in the original base file.

I guess go straight to the 40 and see what she does.

 

I had mine at 33mph with the 60e and 4.10 gears. It worked well there.

 

Tgui, yourealso running stock tires correct?? Thinking with the 35s ill need more

 

Mine were larger than stock, around 32in and a crappy 3.42 gear with a Circle D 2500 TBSS Stall.

Stock Engine too!