[Pete Munroe]

On my 67' Corvette, the Holley 1850, after about 10 years, would scream so loud you could hear it on the freeway.

Eventually I took the carb apart and used 220 wet/dry paper to sand the flats on the main body...metering block...float bowls...any surface that was supposed to be flat...

Used a milled steel saw table as the base when possible, moved the piece in figure 8's over the sand paper with a little water.

The carb was quiet for several months...eventually the noise returned, but for a while it was quiet and didn't weep gas from every joint.

So, a vacuum leak, why ?..... something is not sealing...you may be able to sand it flat or have it milled....or if the old pot-metal castings are disintegrating....give it up and get newer parts.

Not your imagination, they can make horrendous noise.

Pete