When performing a Turbo swap from the 7mge to the 7mgte engine WITH TRANNY, will you have to replace the exsisting driveshaft?

Yes, slightly different lenghts and a different number of splines.

you said slighty longer. and different splines. How about on the differential side. are the spliens the same. Or will I have to replace that too?

The differential sides are all the same, it's four bolts. The gears inside the differential are different however, your going to be stuck with a 4.3 final and probably an open diff if you don't have the sport package.

nah I have the sports package with the lsd so that hsouldn't be a problem. Where's another question kind of off topic but w/e. Does anyone know of any reputable engine suppliers that would carry the 7mgte with tranny ,ecu and wireness for not too too expensive?