Some one has told me that GM made some of the 2001 and 2002 HD trucks with newer or older (98 style) body style. I was unsure as to
what he was telling me.
Possiabley have to pull the bed off to get to the fuel tank (diesel) to replace the fuel gauge sending unit. He said the newer style was a
royal pain to pull but the older style wasn't that bad.

This is my wife's truck (2002 2500HD Duramax) and trying to find
out is there any truth to what he said .................... if so then
how do I figure out which one she has.

Thanks !

Your '02 2500HD is a new body style truck. The Duramax was never in the old body, those had the 6.5TD and the 2500HD was never available in the old body.

It really doesn't matter, pulling the bed or dropping the fuel tank is about the same on either one.