Those fasteners you used will get loose. You should use Gr.8  Body Bound Bolts with HD frame washers and lock nuts. Use reamers    21/32nds. for 5/8  25/32nds. for 3/4  You will drive the body of the bolt into the hole. Hold the bolt and impact the lock nut,  We use Huck Spin but the machine to tighten is too expensive.