The tires are stock, but the chains are not. I made the chain set to nestle in the cupped out portion of the lugs, and ride higher on the sidewalls. Needed longer side chains and shorter cross links than what was/is commercially available.
I gained about an inch clearance by turning the rims and that gave enough distance for the chains to not interfere with the fenders. The inside is just a hook with no extra take-up links to slop around.
Now since that time, I have added two inch spacers for more side-hill stability, but not for chain clearance.