For towing you want to keep away from high compression ratios and long duration cams, unless you want to spend half your trips in second gear trying to cool the engine down after every little rise in the road. Been there, done that! Get a cam made for a tow truck or SUV, and put on a free-flowing set of exhausts, with X-pipes. The biggest radiator that'll fit is a good investment, too. Remember that, just because the guage says its running cool, that doesn't mean the valves and pistons aren't too hot.