Any LowBuck but STRONG overdrive option?

No Mopar auto is an easy swap. You would want an earlier "H" (hydraulic) IE 46RH as opposed to an RE (electronic) out of the later vehicles. Hydraulic ones are hard to find. 727 based are not an easy physical swap and either 904 or 727 bases swap requires extensive crossmember re-fabrication There are threads on here showing some good details.

There is what is called gearvendors but they might be "cheap"