jgetti,
The 3500HD front axle is about 10" to wide, each tire will be about 5" more outside, partly outside the fender.
About the Dana 70 front with the 10 lugs, I have seen about two of those in the past 6 years. The two wheel drive versions with the I-beam axle are much easier to find, and still 9" or 10" to wide.
A more suitable front axle as far as steering parts and using the original gear box would be from a Chevy P30 chassis with the I-beam front and 5 lugs, also some of the big vans have the same axle and steering arms.
I believe that the 19.5" wheels with the tallest available tire, 8R19.5, is still to small, about 32". They look great on a 1 ton, but to small on a 1.5 or 2 ton.
You may get some ideas from looking at my pictures on the link below, as I used a 3500HD front axle and a Dana 70HD rear from a P30 under my 48 6400.
Grigg