Need an expert on 90s 3500hd dually trucks

[LynnB]

As some of you guys know (or forgot, as I am not on here often) I have a 49 Studebaker 1 ton with dump bed. I swapped in the engine and trans from a 1972 C60. Problem is the trans is a NP542L, meaning I have no OD. With the factory (Studebaker) 6.66:1 rear I am screaming at 4200 rpm at 60 MPH on the highway. Frankly, I don't drive often on the highway, but would be nice to have EITHER of the following:

1. NV4500 OD trans, which, I believe is a direct bolt in. One inch input shaft and same length;

OR

2. Complete dually rear axle assembly with drum brakes with a 4.10 ratio.

I believe the 6.5 Diesel 3500HD manual trans trucks from the mid 90's had both of those.

I would prefer to do the transmission swap. If I swap rears, I will also need four wheels for the rear, as the bolt pattern is different. Also, I know some guys hate them, but I really want to keep my 17" split rims.

Any gurus on here that can tell me which years of 3500HD dually trucks came with the above trans and rear?

Any help greatly appreciated.