Are you aware of any aftermarket tag axels for 3/4 or ton trucks? A number of years ago I recall a such a critter on trucks used for 5th wheel towing or hauling heavy loads. As I recall, it was a torsion bar design the tag had contact with the ground at all times. the tires where the same tires as were on the truck. The tag was mounted behind the rear axel. I do not recall shocks or springs, I think the torsion bar did all the work. Thanks in advance, John

The new magazine from Primedia "Diesel Power" has a custom twin screw F350, but all the ones I've seen have been custom built.