Steve, I wish I could help, but as you indicated mine is not on the road yet. Body work is holding me up. The reason I decided to narrow mine had more to do with getting the wheels inside the fenders that it did with fitting the crossmember to the frame. I initially mounted it with 3/4" thick spacers on each side. There is no reason why this would not work OK, but I did not like it, so I narrowed it using the method Mobileortho and others have done.
I do not foresee any problems with future alignment even though I have lowered mine with drop spindles and springs. It looks good now, like an OEM marriage. I had another Bolter, TNtrucknut come by to study it. He has done several subframes and other swaps, but liked the way this one turned out.
If the wider fenders from the bigger AD trucks were used, I think the wheels would fit inside them great. I'm not sure if you would need the whole front end from the bigger truck, or just the fenders and grille. I have seen some nice front ends for these big trucks go for cheap since everyone only wants the 1/2 ton stuff.
