55 GMC 370 frame spec???

[7 Devils]

This might have been covered on here ate some point but I cant seem to find it, so I'll ask here. If someone knows of a thread that covers my questions please redirect me.

I have a 55 GMC 370 (Serial 371 R Y2834) and I want to do a 4x4 conversion on it with a more modern setup while maintaining that big tall feel.

1. Does anyone have or know the frame rail widths on the front and rear?

2. What newer front/rear end components are easiest to bolt up to this chassis? Mild fabrication isn't a big deal.

3. Is converting the factory frame more or less expensive that putting the cab on a newer chassis?

Thanks for any answers or a point in the right direction. This is my first medium duty chassis build. I'm much more familiar with hot rods, drag cars, and light duty 4x4's.