70 Barracuda is going to get a new bullet and rear end. The car has not been gutted and won't be a lightweight. What do I need for a driveshaft? What is a good diameter, wall thickness and material to specify? I am not class racing so no need to get exotic. Probably use 1350 joints. What kind of yokes are normally recommended for something like this?

In theory, there is no difference between theory and practice. In practice, there is.