96' E-350 Driveshaft?
 

So I just purchased A 96' E-350 7.3 with a nice body and 180k miles on it at a steal at $1800... the only issue it has is the driveshaft which I believe is bent cause I get a driveline vibration that increases with speed and only starts around 45-50mph and I know its not the tires cause I balanced them at my shop.. Now my question is, can the newer aluminum driveshaft in any way fit on my older van? Direct swap? Swapping out the yolks, Ect.? I would rather have the Aluminum drive shaft to lighten up my rotational mass to help with fuel economy plus, I won't be doing any towing, or loading the van too heavy, so I don't really care if the steel driveshaft is stronger or what not.. BTW it has the E4OD trans in it. Thanks.

-Anthony

Have you been able to place the vehicle on a set of jack stands or lift and observe the driveshaft in motion? If not, it could be a simple matter of having the shaft balanced.

I can get a used one pretty cheap and I'm not worried about if its thats the issue or not the question I have is if I can in any way get one of the newer aluminum ones to fit on my older van which came with a steel one.... If its direct fit or if possible swap the yokes out from the steel driveshaft to the newer aluminum style

I wasn't aware that an aluminum driveshaft would make that much of a difference with a big moose 7.3 in there. How much difference does it usually make?