Transmission shifting

I have a 79 with a th350 trans the trans is basically stock with a smaller converter the car has a 4.56:1 rear end since I switched the rear end it wants to shift from 1st to 3rd you can bearly feel it touching second is there anyway to adjust the shift points in ths trans...

  are you sure everything is hooked up(vacuum to modulator, properly adjusted tv cable)  you can get an adjustable vacuum modulator but this will only adjust the shift point of both gear changes. 456's are a pretty high ratio is this a  car for track use only??  are you sure your not getting second, changing the rear gears wont change the trans shift feel .  did it work before any other mods(shift kit, torque converter)  need some more info    kurt