Supplemental electric fuel pump and regulator rec's
I'm pretty sure the "issue" is the carb, it's sensitive to float level and the bowls aren't very big. I've had it since 2016 and since moving from Colorado last year and having to pretty drastically richen it up for the change to sea-level air the fuel system can just barely keep up. I never had this kind of issue back in CO when the power and fuel demand was substantially lower. I've wanted to swap to a DP-style Holley for a while because this Street Demon just isn't very tunable and not as well suited to hotter engines, I'd say mine is on the border (ported RPM heads and port-matched RPM intake, 222 @ .050" cam).
Engine Masters did a test of this carb in a new-style "street carb" shootout and also found that it leaned out slightly at higher RPMs. I once also talked to a guy at a race/show event who worked at a performance shop in TX and explained how these carbs need extra fuel at higher RPMs, gave me a detailed rundown of the ideal setup... main thing I remember is a rising-rate regulator but idk much about those? Probably easier to just find a good used 750 DP.