[brad_man_72]

The driveshaft shop will need all of the driveshaft assembled to PROPERLY balance the shaft. This will include the rear section. This is what I do all day every day. If your driveshaft shop says otherwise, slowly turn around and walk out the door with your driveshaft and find a real driveshaft shop. They will also need a tailshaft to center of carrier bearing and center of carrier bearing to center of rear ujoint measurement from YOUR truck. Unless you have adjustable suspension don't fall for the hype of the billet/poly carrier bearing that also requires a slip and stubin your rear shaft. Now would be a great time to get some spicer 5-1310 non greaseable ujoints as well.
Assuming you have a light duty carrier bearing setup....