I've seen it done on a panel of that vintage. It looked pretty ugly underneath. I saw it for sale for $2,500 and feared that at $25 I'd regret getting involved.
I saw a 55 like yours that appeared to be professionally done sitting for sale a few months ago. It had 20 inch wheels and duals in the rear. I figured it was a light weight monster truck.
There is a 55 1st GMC pickup I see from time to time that has 1/2-ton 4x4 running gear. It looks like Blazer stuff and is pretty clean. It belongs to a doctor and he has it serviced at an expensive shop. I drive past that shop often, and that's where I most often see it. So, looks nice, but spends a lot of time at the shop...
25 years ago I had a '51 GMC sitting on 1-ton military type 4x4 running gear. I didn't build it, but I was forever fixing something on it. However, if it were me I think I'd sereously consider that approach as dukw45 suggests.
I see these conversions from time to time, but they are always for sale, or sitting at a shop. My conclusion is that its really hard to do it right, and most people aren't happy with the end result...
