I assume nothing, if they would have tuned the carbs and ignition timing, they would mention it.
Running 11’s and 12’s doesn’t prove ****, just the motor making at least 350-400 peak hp. You can run 11’s with 900 Hp if you can’t drive.
It’s apparent to anyone reading your post that you have a hard on for manifolds. Cool, run manifolds. You don’t care about an extra 9hp? Sweet, I don’t care about you making 9 extra Hp either.