Has anyone narrowed a suspension Xmember?

[yossarian19]

Hey folks,
I've got a '57 that I'm trying to update to tapered bearings, ifs, disc brakes etc.
One route is to take a C10 cross member + frame section & narrow the '57's frame to match. I don't want to for a few reasons.
The other way, which I'm hoping one of you knows something about, would be to cut a section out of the center of the C10 cross member & re-weld it all with some fish plates overlapping the cut section.
It looks to me like a bandsaw, a welder & some 16ga sheet should do the trick.
What say you?