If you're looking for milage you have to get into the tuning. These cars don't tune themselves like a modern car so you need to dig into how to set and control the timing curve, and then how to tune the carburetor. You should have the vacuum advance connected, and you should know exactly what the initial timing is, and the centrifugal amount and what rpm it starts and finishes at. Once that's set you can plug in the vacuum advance and set the carb. Chances are it will be lean which when combined with the timing you gives you the pinging. You will need the Edelbrock strip kit for that carb. Always do timing first, carb last.