Hey guys thanks for looking
I dont have access to a good book and im curious
on the back of the carb body (block off) there a series of holes that are plugged inline with the high speed air jet (far right and far left) the top hole is open and the middle is plugged and bottom is open. Why did holley plug them, why are they drilled, and if there plugged then why do the metering block gaskets have them stamped out?
Thanks

 

I'm having a hard time picturing which holes you mean. But, Holley makes it's gaskets to fit a huge variety of thier carbs. Some have provisions and passages others don't. On any given carb, there are going to be some passages that have holes in the gasket but don't exist or are pluged in the carb. it's nothing to worry about.