Who's using o'donnells

[SixVi6-Camaro]

yeah I bet its just the mixture of the fuel and plug not agreeing with the engine. A good tip when you start having problems like this is to get a notebook and write down the plug, fuel, engine temps, needle setings, even roughly how humid it is out then a couple notes on how it was running. I do that with my engines until I find a combo that I really like.