Hello I’m new to the group and I hope I’m in the right group here lol.
I have a 2003 Chevy duramax where the cab and box is pretty much shot my question is I found a good deal on a cab and box same year but was a gasoline truck what issues could I run into swapping it over to the diesel chassis thanks

 

Personally I wouldn't even attempt it. At 2003 model year, I think you'd be better off selling the vehicle for whatever you can get, and find a similar one with a Duramax diesel motor. You are going to spend lots of money and time on this vehicle if you decide to do so.