You hear folks like me talking about Raptors as necessary for performance modded bikes.

Vac comes on your Savage in many many little vac pulses, of varying strength and duration.  Your vac petcock in normal mode flows the gasoline in the same way, little spurts of varying strength and duration on top of a steady state suction level which varies at the same ratio that your CV carb varies it's vac level (throttle response).   It is the same suck after all.

Low throttle, low suck, low gas flow.   High throttle, lower suck than you would think, sometimes too low a gas flow on an ailing vac petcock.

This is because at full throttle on the Savage the vac level dips a bit, causing the stock vac petcock to deliver a little bit less gasoline than you would think.

Performance modded Savages use a lot of gas at full throttle.   My vac unit wasn't delivering the gas I needed at the topmost part of a hard run and I got the stumbles.

Raptors don't care -- they deliver max flow all the time.   I do not get stumbles any more at any speed.