Speedway Motors can help but you will also need a torque arm to replace the rear radius rods.
I question whether or not the stock rear radius rods are really strong enough and would not rely upon them to "do the job."
http://www.streetrodderweb.com/tech/...ne_conversion/
Be sure and read ALL of this thread and links provided.
http://fordbarn.com/forum/showthread.php?t=88576
A huge amount of information on this topic is available on www.jalopyjournal.com
Do a search using terms such as:
Open drive line conversion
Converting torque tube to open drive line
Torque arm