I had my stang in the shop a few weeks ago and while it was there I had them adjust my timing to 14* since I didn't have a timing gun. I've been running 87 in it since then, mid grade, and a few days ago my dad drove it and filled the tank with 85. I don't hear any ping and there aren't any problems with it, can this be right? I read all over that you should run 91 octane with 14* or you'll hear deteonation. Could there be soming janked with my timing, and if not think I could go higher and just use 87 maybe?