How many miles?
The distributors in these trucks are bad for eating the drive gear.
The play that develops will mess with your timing.
It's a sacrificial part anyways.
The old SBC/BBC's had a replaceable bronze gear, but I believe that that bit of common sense has gone the way of the Dodo.
IIRC, a new distributor is the only fix for a bad gear on these trucks. Even still, easier to replace the distributor than the cam.
When mine needed replacing, I found that, at first, the pinging would only be apparent when under hard load. It became more so at lesser loads as time went by.