If we ream a hole, so in how much ovality is hole manufactured. (The one which is reamed)
isn't only a tolerance in size important when reaming.
a drill will get you a oval hole of over/undersize.
a ream gets you round but over/undersize.
and boring gets nice size round holes.
double check all i might try to make you believe or prepare for the worst.
Finally CHIPS you can have as much as you can without the doc. complainting about your cholesterol.