I don't think the LD340 would hold it back much compared to an AG. I think @pittsburghracer tested the Speedmaster not too long ago and it significantly restricted flow out of the box? I could be misremembering though.
The Speedmaster intake has its place but it’s not on a performance build. It seems when they copied an intake they copied the LD4B instead of an LD340. The runners sizing is small.