https://number1-hobby.com/products/o...-air-glow-plug

For a racing brand engine you need a 5 or 6 onroad plug from Picco or Novarossi (or even HPI), the A3 is much too hot and now named as a 6 is too confusing compared with normal plugs.

Forget the factory settings, they are not right but make the engine startable. If the engine starts it is wiser to learn how to tune, then you never need the the factory settings. And Picco does not list much of older engines but maybe you will find something at Trinity because in that period Trinity had a same engine from Picco,