high shift points/late shifts trouble staying in a higher gear

[bobo]

i just bought a 88 4x4 with a 700r and im having this same problem and i dont no where to start

 

[zackyg]

i have a 88 Chevy with a turbo 400 tranny and mine does the exact same thing. if i gas it to fast when it is cold it will become stuck and wont shift into 3rd. my dad told me it was possibly a bad torque converter?