Are the driveshaft the same for the 3.8 -4.6 automatic or 5 speed?

 

It looks to me that the V6 and V8 for these year cars is different. Looks to be a spline difference in the output shafts of the transmissions. There may be a length issue as well, but I kind of doubt it. I looked them up at American Muscle and they were not interchangeable.

As to manual vs automatic, either engine, the aluminum driveshafts from Ford are the same for either transmission, but different according to engine. Oddly, for some reason there's two different ones from another brand for the GT, not sure why they differentiate between the manual or automatic.

Welcome to the forums! Hope that helps!