LS Swap/SWB Conversion Driveshaft

[cebra]

I have found a 2WD NV3500 (Silverado) transmission I am going to pull tomorrow and am having a hard time figuring out a game plan for the driveshaft.

I currently have 350/TH350 LWB with 2 piece driveshaft.
I am converting to 4.8L LS/NV3500 and cutting 12" out of the frame for the SWB conversion.

Should I take the Silverado driveshaft to have cut down or only the front yoke? The NV3500 will sit quite a bit further back than the TH350 and removing 12" I assume I will convert to 1 piece DS. Any recommendations are appreciated.