I have made 2 inch wider AD truck fenders by starting with two sets of fenders. I cut one set at the bolt flange and the other set just two inches in from the flange. Then weld. Another option would be to split the fenders and add a strip of metal the amount needed. The ones I did are out back in the scrap pile. Made the truck look like a 1 ton. John
Buy fiberglass fenders that are 2 inches wider. Not a fan of fiberglass but bang for the buck 2 inch wider fenders are good.
On then 42 Chevy I am building, I cut off the mounting flange, and added a 1 1/2 inch strip of metal. A lot of work, but the fenders look great when done, and that did the job to get the tires covered again