14 bolt and a shackle flip, Flex and Driveshaft Questions.

[JohnyWard]

So here is the situation:

I have a 14bolt and a DIY4x shackle flip on a 1971 blazer. It has a 6.2 diesel/ NV4500/dodge(ish) np208 and I know I need a new, custom drives shaft.

The TCase has the standard GM flange for a future EBrake and I know I want a CV style shaft. The 14bolt is a 1350 strap yoke.

If I measured everythin correctly, and I plan on doing it at least once more, then I only need about 1.5 inches of shaft play on compression max (ie the drive shaft would be flat and the axle tube contacting the frame) but I have NO IDEA how far down the axle will travel with the flip and stock springs. From what I understand, most rear shafts have 4" total slip in them, this should give me around 7" of droop.

So here are the questions:

Does anyone know how far down the suspension will droop?
What are people reccomendations for driveshaft manufactures?
And likely more Questions to come...

Thanks