Pulling away from a full stop in Drive truck acts like it has a 2500rpm stall converter and then bucks until it finds a gear. Does the same thing @ 65 on Hiway as it can't find a gear.
Yet Transmission seems "OK" if OD is off and you manually shift. So? Rebuild or Replace??

 

Check for codes ?

 

CEL on?? If so, get the codes.