best cast iron head on 355 with rochester 2G

I posted this in drivetrain, but I thought I would put it here as well to get suggestions.

Im looking for everyone's opinion on the best cast iron head for a 355 with 11:1 compression (60cc chamber) with a 1 3/8" gauge legal rochester 2G. The rules are no vortecs and no closed chamber heads and no 2.02 valves

We run on a 1/2 mile slightly banked oval and turn around 6700 to 6800 rpm with a 462 head right now. Final gear is 5.74 which is running a 1.68 2nd gear with a 3.42 rear.

We are good threw the corners and car handles great but get pulled a little down the straight. Our carb is an off the shelf Jet stage 1 from jegs, would I get that much more out of a SMI or C&S carb

Willing to consider something from castheads.com if they are worth the money.

thanks for the help