A few comments regarding the drive shaft shortening, First of all, shortening by two inches is to much. I decided on 3/4" (19mm) to a length of 556mm and this worked perfect in a 1978 280Z.
I tried Standard Parts Corp. in Richmond/VA but was told that this type drive shaft cannot be shortened due to it's geometry. After this and based on information I found in this post above, I, too then went to Ballos Precision Machine in Richmond and they were willing to work with me. The person to talk to is Stewart Heider. His initial quote was $150-180 which included replacement of the barrel. In the end I only paid $95 which included balancing. They managed to shorten the drive shaft by cutting the rear end only and re-weld.