There's a few things i'm curious about with this swap...
1, is the Aerostar shaft itself rated to the same torque levels as their Motorsport version that they sell for Mustangs....otherwise the only gains i can see would be a slight loss in weight/rotating mass and the better dampening of vibrations that aluminum shafts typically provide,
2, how strong are the parts store universals you bought? These may end up being the big weak link, and if your car is making a reasonable amount of power and you ever race on slicks, you better get yourself a drive shaft loop....
I'm not knocking this idea AT ALL, i'm all for it....i'm just curious. I've always got my eye open for an AWD Aerostar, they're just very uncommon around here.