I hope I am answering some of your question and not confusing things too much. I believe advanced design chevy 1/2 ton trucks from 47-54 had the torque tube rearend. 55-62 they switched to open driveline. Since you mentioned nascar I wasn't sure if you are thinking of a rearend swap into another car, or converting a truck to open driveline. In my case, I have a 51, and I may try to find a 55-62 pumpkin to swap into my rearend to get the open driveline. In these trucks third member can be removed from the font of the rearend, like a 9 inch ford. Here are some pics where someone did this swap.
http://www.flickr.com/photos/dodsonb...7600834633728/
What someone mentioned earlier is that if you used the torque tube housing, you would have to weld on leaf spring pads or some sort of bracket as the rearend pivots, with the torque tube. Sorry if thats not what you needed, just some torque tube swap info if anyone needs it.
Corey