G'day BSA500, Funny you say that as my '51 A7 with a '56 SS top end is like yours and only pings if a plug is on the way out. The timing is std at 5/16" but is running a little rich with a 32 concentric and Boyer ign.
Groily, that all sounds like FUN.
Beezalex, you are very correct. My excessive pinging on the A10 is more than likely due to the 10.5 pistons and the sharp valve recesses which will be rectified next head off.
Cheers
