No the driveshaft doesn't need to be shortened, but you have to change the yoke at the trans, it has differant splines. The best way to put the longtubes on when you install the motor( I can speak for BBK's) is to get the motor over in the car and close to mounting and put the pass. side header in from the top and then guide the motor down to the mounts. The drivers side slides right in with the steering rod unbolted. If the motor is in the car you can install the pass. side but you need to remove the starter and jack up that side untill it slides in.