Welcome aboard Graham. That's a sharp looking Demon you have there. Does the rear end need Sure-Grip additive? If it's not in there, it will make the clutches bind up and when you make a turn they'll snap/chatter like crazy. Good luck with it.
Thanks Sid.
For a few years I had borrowed a set of 3.91 gears from a friend. When I put the 5.38's back in, I added the sure grip additive from my local Chrysler dealer. Then the car sat for 5 years. Hopefully Doug can get to the bottom of it soon.