I have a 78 f150 that has a 4" susp. lift and 33x12.50x15 mud terrains on it. I am looking to get a set of all-terrains for the highway but am not sure of the metric sizes. I like the look and feel of 33x12.50s but dont know how that translates to metric. I want a set that has good road traction but i dont want to neuter my truck with little golf cart looking tires either. Any suggestions?

 

Also i am keeping the mud tires

 

Why do you need metric sizes? Every all-terrain tires I know of is available in 33x12.5r15

BFG A/T - http://www.4wheelparts.com/Tires/33x...&t_pn=BFG09681

Dick Cepek - http://www.4wheelparts.com/Tires/33x..._pn=M%2fT13253

Mickey Thompson - http://www.4wheelparts.com/Tires/33X...2fT90000001912

Pro Comp - http://www.4wheelparts.com/Tires/33X...&t_pn=PCT55033

And the last is a mud terrain, but I got over 60k miles with my Toyo M/T...Highway mileage traveling back and forth to college, etc. My Mickey Thompson Mud Terrains have gotten me another 30k so far with around 50% tread left. Mud terrains these days can last a good amount of time.
http://www.4wheelparts.com/Tires/33x...t_pn=TOY360100