I have a 70 Camaro SS with a Stock 350-300 in it. The engine has a 12:1 compression ratio so it requires high test gas. I have been running High test with ethanol fuel and so far no pings. I don't know if there is any internal problem with the ethanol. I just saw the local Racetrack has an ethanol free gas available. Should I look in to this or since I haven't heard anything just go on oblivious to possible problems. There are a lot of people on this site that know a lot more than I about this subject. Does anyone have any comments? Ethanol high test or non ethanol lower grade fuel? Thank you.