85 S-10 wont shift correctly

I need help before I kill my hubby because of his temper. He has an 85 S-10 pick up with a 2.8 motor and a 700R4 tranny. The tranny was just rebuilt(by a shop) and my hubby installed it. He has installed them many times but this time it just isnt working properly. Truck goes into gear ok but will not go into 2nd gear until about 40mph and hits third at about 57mph. This causes the engine to rev really high like the damn thing is going to blow up. We have checked the fluid, adjusted the TV cable and shift linkage. Any suggestions as to why it wont shift like it should????

any advice appreciated!

Holli

sounds like a vacuum modulator problem