What is the standard jetting?
Stromberg 97: 0.045in main jets and a Number 65 power valve. All new Genuine Stromberg 97s are supplied with this as standard.
Stromberg 40 and 48: 0.048in main jets and a Number 63 power valve (a 63 PV is a bigger jet than the Number 65).
Stromberg 81: 0.035in main jets and a Number 71 power valve.
Remember though, that this was the standard jetting on 1930’s gasoline at sea level. Ford supplied smaller jets for cars supplied at high altitude. And modern gasoline is nothing like it was back then. Nowadays, you need to consider the best jetting for your own application, and the local gas and local elevation, engine tune, the season (ambient temperature and humidity), your performance and economy expectations, and more, can all have an effect on the jetting you should use.