If you really want to help your engine, optimize the squish. I found out when I rebuilt my top end that the squish was like .045-.050" on a stock engine. An excessive squish is asking for knocking and preignition. Get that down to .030" and you can run up to 11:1 compression on 91 pump. That's pretty stout for a street performer. I'm running 10.5:1 on 91 pump in Vegas summers and I have had no issue with pinging.