I made this bar out of mild steel 13/8 x . 125 wall. Twisted it in the first hit. 11.17 starting line ratio, 860 hp,, 4.56 gears and 33x15x15 slicks. I went to 1 3/4 x .134 wall tube, no problem. It is all about leverage and torque. Combine too much of both, and anything can bend or break.