Offenhauser 4 barrel with what carb?

What kind of tuning did you have to do to get the 390 to work properly?

not a whole lot. idle mix so it still runs happy and doesnt burn your eyes when you are sitting somewhere idling. a couple jet changes to get in the right range. other people may get more into it but thats all i felt i needed to do. ran great, no hesitation and awesome 24 mpg.