just measuring my original 4.5" rims it looks like the offset is +0.5" - perhaps somebody can confirm that I'm measuring correctly. If that's the case, then I have a hard time thinking that the 0.5" difference in offset would be a big deal with regard to the tires hitting the frame, but perhaps somebody with more knowledge will weigh in.

I also searched for discussions about using trailer wheels on 1/2-ton trucks but didn't find much, all I could find was discussion pertaining to the 3/4-tons and 1-tons.

Are any of you guys using trailer wheels on your 1/2-tons?