SP2P 2bbl worth the effort?

I think the OE 4bbl. & the Performer are about as good as it gets intake wise. If your carb is jetted to be dead on to slightly on the lean side for cruise, then that’s set. The best I can suggest after that would be a un restrictive air filter. LOL

Exhaust wise, be it off exhaust manifolds or headers, your dual exhaust is the way to go. Muffler choice has a small effect. It can be helped (minimally) with a H or X.

Otherthings, going on down the line would be ignition. I have found good results with the MSD 6A box and the stock distributor.

What is your tire size and gear ratio?