<VV> Replacement Holley Carb Part Question ?

[GYoungwolf@aol.com]

I know that quite a few folks have used a Holley 2110 - 300 cfm Bug Spray - 
carb for their center mount conversion, so I have a trivia question on it. Some 
of them have something called a spark valve on the side of the throttle body 
(looks very much like a power valve with air intake slots). Does anyone know 
how it works or what it does? Some carbs have a plug instead, so it can't be 
all that critical, (I don't think). I have a core with a frozen/corroded valve 
and need to decide whether to plug it.
Thanks,
Grant Young