My personal opinion is that regardless of what size tire, transmission and rear gear ratio you use in that 1 1/2 ton or larger truck, youll have to be going down hill, unloaded with a tail wind if you expect to see 60mph with a 235.
Even if you stepped down to a 1 ton truck, with a gear ratio in the 4.somethings, you would probably still be to darn low to tow anything very fast for very long.
Jeff
