Step 5: Building the driveshaft
After you have the engine, transmission, and rear diff driveline lined up perfectly, I recommend you calling the DriveShaft Shop and have them build you a custom spec driveshaft for your specific application:
The Driveshaft Shop | 2010 Website Coming Soon
I've worked with DSS guys on over a dozen projects and they are VERY nice guys. Don't be afraid to call them and pick their brains. They can help you get the correct driveshaft for your application.
The price is actually not that bad. A custom shaft costs about the same as a stock-spec shaft. Talk to them.
You can talk to them about steel vs. aluminium while you're at it.