I just purchased a cheap 4 barrel carb on ebay and in the process of the rebuild noticed that it had this aneroid cavity. My book by doug roe(very good book) covers everything there is to know about rochester carbs, except the setting on this cavity. the book does talk about the fact that it was a featured used in 1975 carbs and that it was factory set.

Is any of you wizards a carburetor DUDE?

if you are and can give a me an idea as to how many turns this should be set, my GS and I would be very appreciative. My mechanical wisdom says to set it half way down and go from there.

Thanks