why would this car vibrate under accel on 1994 Nissan Sentra

the car has only 36k miles half shafts have been replaced with rebuilt no transfer to steering could shafts be defective

It isn't a misfire is it? IF not, it sure sounds like it is the cv joints/axles to me! Also check engine mounts. Let us know what you find so others may get some help with simular trouble.