Edelbrock LD340 Intake Manifold Usable Max RPM?

Did you even read the OP’s question?
I was just answering with my experience not what an expert did on their engine and “yes” compression plays into that mix all day long not just cam and head flow. Does Buddy Vic Bloomer run an LD340 on that engine?

He doesn’t, but if he did it would easily be capable of running well over the OP’s 7 k question.
You’re the one that says they stop making power at 6800. My point is there is no set “ limit” of where they stop at. Other factors come into play.
Compression isn’t a big factor in rpm. Vic’s motor is around 10 to 1, if not a hair less.