My 302s I did that, broke a Greenlee tap off in one hole, so be careful. Plugged all the other holes with some short bolts I had found in a parts drawer, plugged the "tap hole" with JB Weld.
10,000 miles later all are still plugged.

BTW, I used a rotary cutoff wheel to take off the bolt heads. May be cheaper than setscrews.

R.