i may be preaching to the tube gods here. and take no affense to this but i used .125 wall dom to build my cage. i have see guys use much thicker on links and sleeve it and bend the heck out of them. i used 2" od 3/8" wall dom on my lowers and 1 1/2" od 1/4" wall dom on my uppers. some people might say that is overkill but i say just right. nothing like your axle falling off.