With your combo the only intake that might be a little better would be and Eddy Air-gap. A single plane will hurt low end tq more.

I prefer the AVS over the holley by a ton, they are way easier to tune and don't dump fuel on your intake when you change fuel metering. They will get better miledge on the street and less tendancy to foul plugs, blow out power valves...

I agree that your combo can make a lot more power with a bigger cam carb and porting but with out doing all the above you will not gain much from just one mod.