Thanks for the replies. I think I am going to go on the skinnier side of things. Since its a light engine (relatively) and I dont have much power.
MTs 255/60 and 215/70 look like a good option. Maybe 235/60 on the front.
Shell Valley has given me their suggested road setup. Spring rate, F350 R225 so that will be the next thing to look at after changing tires.