A friends father welded up some square stock to some 1/4" angle iron, we drilled the angle iron for the rear bumper mounts on my cuda & his charger, slid the stock into the rotis arms & drilled & tapped the rotis arm & put in a bolt to lock em in, this is the best pick I could find , not very clear, if I can locate the pics I took of the part we made I'll post it later! Rich.