So fellas, my camaro was running the best it ever has and on Friday night leaving the track unnoticed it started to act funny. I noticed around 2500rpm it would sound like a spark knock but it was a different kind of noise. Now it back fires out the carburetor, but it's not a flame it's just raw gas that comes back out when you rev it up and when you turn it off. Since it randomly started doing it I checked the timing and played with it some but that has no effect, I even messed with the Axel pump on the carb and that does nothing either. I even pulled the valve covers off and checked the rockers but it all seems good... anyone have an idea?