Glen Bryan

I've got a 1997 F150 with a 4.6L V-8 with 170,000 miles. We got it about 100,000 miles ago, been my sons most of the time until he moved over seas, now its mine. Anyway, it didn't get the best of care, hit and miss on the oil changes and maybe one tune up a long time ago. If i dont run 89 octane in pings really bad when i accelerate, and lately it seems to be pinging some even when i do run higher octane. Any suggestions on where to start would be appreciated.