I made some snow chains for my Warhead (see "Snow Chains, No Snow" in the MT section) and I used some pretty stout chain and I would not recomend doing that. I trashed my trans and i think it was do to the extra weight from the chains. I would suggest to try studding the tires. It really doesn't take much to get that little extra bite. As far as breaking it in in those below 0 temps... its not worth it, really. I know you have the itch to get a new truck broke in but, between keeping it warm enough, getting it to start, and the brittle plastic parts, its more of a hassle than its worth. Just wait till it gets above freezing and you will be happy you did.