Wrong distributor for 69 318?
What have you changed in the engine build that would warrant the initial timing be changed from the factory setting of “0” to the 13btdc you have it set at?
In other words, if you took a factory original 69 318, and cranked up the timing 13deg...... wouldn’t you expect it to ping?
If you want to an increased initial timing setting on a basically stock engine, you’ll likely have to limit the amount of both mechanical and vacuum advance, along with slowing the curve down.
FBO has limiter plates for the mechanical part.