Hey HevyHauler, It's not just the Tandem '56-'57 Chevy trucks that have the flared out fenders. Those Trucks with the flared out fenders, are the 8000, & 10000 series Heavy Duty Line '56-'57 model trucks. Check out Mike B's website, & you'll see he has a Heavy Duty 8000 series Wrecker, & Heavy Duty 10000 series Fire Truck, that are single rear axle trucks, with the flared out front fenders, extra opening below the grille, & external running boards. Medium Duty 6000 series trucks, that were Tandem, or single axle, did not have the flared out fenders, extra grille opening, or external running boards.