Slant six on boost - upgrade the driveshaft?
Here's the build thread.
Dodge Dart thread on Grassroots Motorsports
This one is one year too new for ball and trunions; it has a conventional slip yoke. Thanks to all who responded; I think I'm just going to have a driveshaft shop swap the rear U joint and shorten the stock tube.
The other option I had been considering was seeing if modern trucks have any worthwhile aluminum driveshafts I could have cut down.