Backfiring, wrong settings? changed the points. Adjustments?

Looking for someone to tell me about one which seems to have broken the rider tab off the points, it was backfiring right before that, and no power. Changed the points to chevy, but now no go, backfired and sent me to the ground with broken ankle. Looked about re ajusting the timeing, but the timing plate doesn't seem to move even thou two long holding screws are nearly out. Would it be better to just trash the point system and go solid state on a '74 or would that be "cheating" LOL max