Hy Perry Dean, that is a spring hanger/bracket, grade 8 bolts would probably be overkill for this job, grade 5 should be fine. If possible try not to have any bolt threads inside the holes in the bracket or the frame, you may have to buy longer bolts and cut them down [longer bolts have a non threaded area just under the head], use "stover" lock nuts on the bolts, hope that helps.
