Looking for the specs on the original driveshaft for a 71 charger with 440/727/8.75 combo. There was not a driveshaft with my car so I need to have one built and would like to give the company the specs of the original piece.

Should 50.75" between center of the joints.

since you're having one built I'd shove the yoke you plan to use into the trans all the way & measure the C to C distance then subtract 3/4-7/8" from that dimention (suspension loaded & assuming flat common aftermarket trans extension housing rear seal)

I took the driveshaft (that was in the trunk) that came with my project. However it has the smaller yoke and the 727 that we put in has the larger yoke. Also the driveshaft was 1" shorter than it needed to be. So I replace the yoke, retube it and install new u-joints...$365. I feel like my dad.... " I remember having them done for $125-$150".

ALL THIS LIST is to 8 1/4" and 8 3/4"

If you want to save yourself a lot of grief and hassle, call these guys:
http://www.dennysdriveshaft.com/

I had four drive shafts built by different, so called reputable companies, and these guys were the ONLY ones that got it right. They will send you detailed instructions on how to measure the shaft for proper fitment. I will never go elsewhere.

Hey! Why are there different lengths for "W" with the 833 having the 383 engine? What is the difference?

Dunno, but it seems is carb related... WHY? I have no idea.

EDIT:

maybe sedans ?

Dropped the "core" driveshaft off at the local "driveline" company yesterday morning. They called last night just before they closed and it was ready to be picked up! I was already on the way back home (350 miles away), so my dad picked it up this morning. He delivered it to the shop working on my car and they installed it this morning! Specs provided above worked great! THANKS