Q-jet jetting ?

[brennecke]

I am rebuilding a quadrajet now, and while its apart I was thinking about rejettting. the primaries look pretty worn on top, so I'm not sure which set I have. The secondary metering rods are CP, which should be fine for a street truck .
I plan to use it on a 350 with 300 or so HP. what primary jets/ rods would you all reccomend? How do I know by the number which is lean and which is richer? I can order anything from 66-78 with the corresponding rods. I'm looking for a mix of fun and economy.