Stock 235 in a 49 3100, with 3 speed and a 4:11 rear. I drive mainly at 35-40 mph but have gone to 55. My tires are out of round and at 50 the truck vibrates/shakes. At 55 it goes away but I am still not comfortable at anything beyond that. Even 55 is too fast for me. I do not need to use freeways basically because there are none here!When I get new tires I will still drive at these same speeds.
