Hard shift to 2nd and 3rd

First off, stay far, far away from a transmission shop that thinks torqueflite transmissions have vacuum modulators, but do nothing only if you like replacing U joints all the time, because if it's shifting that hard, especially at part throttle, you'll begin to think of driveline maintenance as a weekly thing.

Space off the u joints you've eaten with an out of adjustment transmission long enough it sounds like birds chirping when you accellerate, and if you're lucky the rear one will grenade first causing you to replace not only the U joint, but possibly the rear yoke and probable bent and mangled driveshaft itself.

If you're lucky enough to have the front one go first, you'll get to experience the famous Pogo stick effect.