If memory serves, (always suspect!) it was about a 1957 model that was about 30-32 feet long. Factory. It had a 335hp 743T Cummins and a 5 speed tranny. Probably a Spicer. Used all 5. The driveshaft was very very very short and they had to change out the U-joints quite frequently. Angularity problems?
The Crown had a Jake (in 1970) and ran on a rural/remote route including tight, dusty and muddy dirt roads. Top speed was only about 65. I only drove it a couple of times...very very quick. Sometimes one had to pressure spray off all the brown clay from the engine, tranny and pumpkin bottoms.
Only 400 hp? With factory factory parts, the right turbo, changed power and torque springs in the pump and a big air cleaner and intercooler, one can turn a BC2 Cummins into at least 500hp. Pittsburg Fuel Injection Dot Net will make a 750++ if you want one. All it takes is $money$. HB of CJ (old coot)