I spoke with 2 guys today that would likely remember that car if it went through Sullivan's shop, one worked for him at the time and said he would have remembered such a C as that. There would have been no reason to import a car from Florida for a drivetrain, even without Craigslist, especially at that time, maybe you were mistaken about the Florida angle of the story. These guys were incredibly well connected in the Mopar circle here in Detroit. It is possible that it was a local car that gave up its drivetrain for a B body that someone was building, maybe even Sullivan. Anything is possible, of course, it was a long time ago. They did recall a couple of C bodies that came through the shop as doners for parts, one was a '68ish Fury that had a 392 Hemi transplanted in it, it of course was bought for the Hemi. My impression from the conversations was that they would have recognized a rare HP Mopar and they wouldn't have gutted it if it were restorable. These guys were and still are Mopar enthusiasts.