[badluck]

I got a 6.5" full drop needing to go on, but im trying to get everything together for a smooth install. Iv'e searched around for a few hours now, and havent found a straight answer. So how much if even at all, do i need to get my drive shaft lengthed on my 2 door Tahoe. ill be putting 8" springs in the rear with 1 or 2" blocks. If no one knows, how do i measure to make sure i get the correct drive shaft length? Thanks. -Anthony