Holley Emulsion Bleeds

Agreed, block the middle one if it is drilled. They are all likely a .026-.028 hole as mentioned.

Unfortunately, the emulsion approach has gone the way of a sort of monkey see, monkey do mindset. One manufacturer puts 5+ active emulsions in the metering blocks and others think, hey, those guys did it so we should as well. It's a worm hole and not always beneficial.

In many of those 5 emulsion blocks, I block # 1, 3 and 5 leaving 2 & 4 open. Similar to the older 750-780VS metering block approach which was a really solid metering block. Many times that cleans up a bunch of mid range and cruise issues when on the main circuit.