Well, for a higher winding BBC than mine was/is.
It’s an LS5 from a 70 Vette. About all in and done at 5500.
I can say it was coming on around 3/3.5. Up to then not a lot of difference than the factory cast iron intake.
Now to add, I ran 3.07’s in the ‘57 at the time. It matched up well with what the Vette came with.
But off idle was a a game change with the Performer vs it, and since I never stretched the engine, it was fine for me.
Usually went to 2nd at around 5500-5800.