Does anyone know if there is a two speed rear end available that would work in a 3/4-1 ton truck?

 

I have seen and used a few 2 speed rears... all intended for 2 ton trucks or heavier. Usually 20+" tires and heavy. Not suitable for a 3/4 or 1 ton PU at all IMO.

There are a couple of options for overdrive or gear splitters right behind or in front of the transmission... but not the rear end.

Also, the 2 speed rears were kinda trouble prone... a transmission solution is generally more reliable.

 

Didn't some '69-'70 Cougar Eliminators come with a two-speed rear? I seem to remember something like that.

 

There was supposed to be one on the Eliminator car that LM showed Car Craft and was a Dana/Spicer unit. Some people say they were never actually put in production and some people get them confused with the Hone overdrive.
Hone-O-Drive? Overdrive Transmission System | Hone Manufacturing Co.