in the hopes of changing the base plate for something that had provisions for a pcv or vacuum advance.
i have a smallish holley vacuum sec that works well but wanting something larger i could hook up a pcv to and vacuum advance. i knew bg had in the later years changed to a system where the idle could be adjusted with a screw in the middle of the carb allowing more air into the mixture so the butterflies could remain in a more desirable position. and this is what i found.....
the base plate has the provisions, but the main body does not
. you can see from the pic the base has a brass fitting that would fit into the center, this fitting goes in from the top, and then the best i can figure is there is a screw that runs through the body and either seats on the brass fitting or allows air into the stream, via the small slits you can see just below the gasket in the pic. so this carb didn't have the screw so was allowing air into the intake without any fuel, the orifice is probably 3/16" diameter in the brass piece, maybe 1/4".
i guess i got the changeover parts or clearing house deal. i have heard bg is trying to make a comeback, maybe i will address this with him then.
. i still like the quality of the carb pieces, just there qc somewhere went to sheit imo.