Been looking into driveshafts for this and the length is an issue with critical rotational rpm. The shaft, itself, will be about 58" and at that length and a 6500 rpm speed, Denny's is the only one who will touch this. All the others drop out at about 52-4" for that rpm.
I just talked with their phone rep and I will, most likely, be ordering their 3.5" nitrous ready pro package with Mark Williams yokes on both ends. Their 4" aluminum isn't all that much more, but since I need new rear gears and stronger axles too, I'll stay with the steel. Thinking about Mark Williams for the gears and axles too. The Strange gears for street/strip warn they are susceptible to teeth breaking under heavy shock loads and not really suitable for drag racing with slicks...hmmm. I don't need to break them next, so will be talking with Mark Williams about their street/strip gears and axles soon.
Need to decide if I want to modify the axle tubes for bolt in axles first...