Do they make a 1990-1993 dodge dually single cab 4x4?

 

Im sure

 

They're out there, few and far between I'm sure.

 

Yes, A buddy of mine has one. 92 Dually standard cab 4x4 with the 5 speed and a 2 speed rear axle. The think looks like a damn bulldog, its great.

Now for a stupid question of my own, I have always been curious if the 2 speed rearend was an option or an aftermarket addition?

 

Google is your friend

 

Your buddy probably has a Gear Vendors overdrive unit or something similar. Not a factory option.