I have a 1970 Corvette with stock 300 horse 350. The engine is all stock with 10.25:1 compression ratio and a Quadrajet. The carburetor is not original, however. It has not been altered and I assume was purchased as a stock replacement. This is one of those carbs with the large main air bleeds (.125). I don't have the idle air bleed sizes at the moment The idle tubes are .040 and the channel restrictions are .060. The main jets are .076 and the primary rods are .044 at the last step with .026 tips.
The needle and seat, float and seals are new. Float is set at exactly 1/4".The carb has bypass air. Initial timing is set at 10deg advanced and ported vacuum advance.
The problem is with nozzle drip, just off idle as the transition slots are fully exposed to engine vacuum. This occurs from about 1200 RPM as a drip and increases to a splurge to 1500 RPMs then turns into a proper emulsified stream above 1500.
The engine idles fine at 875 RPM and the idle screws are effective at adjusting the air/fuel feed.
What would you suggest to remedy this problem?
I thought of decreasing the idle tubes to .037 but without also reducing the channel restrictions will this lean the idle mixture too much?
Is there a best way to resize the channel restrictions ?
I know in your book you suggest reducing the air bleeds and using smaller jets on these early Chevy carbs but I would rather not have to go through all that.