1993-1995 46RH and 1976 318cu

I have been reading for awhile but looks as I will just have to come out and ask the question.

I have a 1976 Dodge 1/2 ton shorty van with a 318 engine in it.
The engine is fresh and so is the 727 transmission.
I do allot of freeway driving and looking for the Over drive and some better mileage.

Is the 46RH the equivalent to the 727 transmission and the Big question, Will it bolt up to the 318 engine?
Linkage, a little wiring, Mod the rear mount, and drive shaft re-worked would be sweet..

Helmar