Hey there guys. New to the forum. Been searching for days and finally decided to join and ask because I can't find any answers.

99 f250 7.3 4r100

The trans took a crap on a buddy of mine and he couldn't afford to fix it so I bought the truck from him. I got the transmission rebuild by another buddy of mine who has his own shop and rebuilds these things for a living. Reason I've come here is because he's not been able to take a look at it for me just yet so I'm curious as to what it can be and what I have tried. Problem is it shifts fine until you start driving and the truck gets warmed up. Then it gets to where when your dead stop and take off it hesitates to shift into 2nd gear. The only way to get it to shift is to redline it and let off the throttle then it shifts. After it gets passed 2nd gear it shifts fine through the rest and has no trouble.

Check engine light codes are:
P0732 Gear 2 Incorrect ratio
P0781 1-2 shift malfunction

Things I've tried:
Brand new solenoid pack
Brand new accum body
Brand new valve body

Ive only put less than 20 miles on the fresh rebuild. Also today I drove it around my neighborhood and coming up my hill I had to manually shift it into 1st it was not switching into 1st gear coming up my hill and I was almost to the floor barely going anywhere. Any help is greatly appreciated

- Richie