i towed my truck to the rubicon for mcr7 with a 1/2 ton 2wd chevy with a 350 throttle body. it would pull it fine on the flats at like 65-70 but when we hit all the mountain ranges in so. oregon and nor cal it was a dog!. i had just put brakes on it before we left otherwise i don't know how it would have turned out cause the trailer had no brakes. but it made it there and back will never do it again with that truck though.
