Swapping in the 87 auto into my 83 truck required changes to both driveshafts and a "universal" shifter for a 3 speed tranny. I'll figure out the OD part later because this truck never sees the highway and won't miss it.

I think the reason the caravan blocks don't line up to the bellhousing is that they are the narrow pattern. The A 604 mopar tranny for the caravan is an adaptation of the 904 gear set to a transverse format. The only way to know for sure is to measure the caravan block, probably from the same 84-86 vintage.

83 mitsu flat bed 2.6l weber, 88 auto tranny, 2" body lift, 4.625 LSD, 235/85-16E mudders (33 x 9.50).