318: too much cylinder head?

Listen Punk...can I call you Punk?? Ha ha...anyways, mr. frosty (I like snowman better but that's just me) here is the major problem...street/strip!
Anytime you need to have an engine pull double duty you compromise alot...and the smaller the engine the larger the compromise!!

The sixpack setup is very restrictive in OOTB form. So beware!

The heads will not be the cork in this combo, it'll be the small engine + need for street drivability + 6pack setup.
Cam I would choose would be closer to 232@ .050 intake, 242@ .050 exhaust, on a 110 lca and advance it 6°. Don't worry about idle, as you can tune the carbs to work with less than 12".
Now if you were to go with an 8" converter you can run a larger cam.