I saw this on vacation out at Douglas Dam in Sevierville, TN. They used 80 to 86 rear fenders on the bed. Looks pretty good.

 

Definitely different.

 

A for effort but it looks unfinished from the mismatched trim.

 

Good idea, but I kinda like the complete dent look, trim or no trim. Orona has a pic of his truck box sitting over a dually axle and the tires don't stick out that bad. On the other hand, if you use a 89 axle like me theres about a 3" difference in axle size. When I put my box on I'll post pics to show how bad my tires stick out. I'm partial to the tri 5 chevy fender. Guess I'm making some cardboard and paper bucks.