You might need to run a cooler spark plug. What heat range are you running? If you are running too hot of a plug, the pinging will only get worse during the Spring and Summer temps. A cooler plug will allow you to run a quick timing curve and also allow less jetting to some degree.
The brown cam is for the 50cc pump.
Your timing curve looks good!!
1970 YO7 A66 [Canadian Export] F8 Challenger 340 (Currently in shop for stroker assy.)
