Questions for 8 3/4 swap

We are doing a simular swap soon and we have an oppurtunity to have a drive shaft made up for us at a fantastic deal right now. does any body know the exact measurements of the drive shaft that would fit ?

We have a 904 tranny behind a 360 with a 8 1/4 rear end in it now

I have been dealing with a drive shaft place here in Orange County for the last year and they have built and balanced over 1400 drive shafts for the Uhaul trucks . They will cut me a pretty good deal on a new one for the Duster

We are putting in a 8 3/4 rear end in in the next few months but would like to have a drive shaft built for it now while the offer is still good.

Bob / Bryce