Electric choke/rich carb issues?

I have a Quadrate 4 barrel (17080212-1024), mounted to a stock intake on an 84 C20 454. I recently replaced the hot-air choke with an electric choke, and since then, almost every time I start the truck, I get wet, black spatter shooting from the exhaust pipe, along with some fuel-smelling smoke. Once the engine warms (choke opens fully within 4-5 mins), the smoke clears and the truck runs great. With the hot-air choke, this problem didn't happen. Also, I recently replaced the spark plugs (they were all fouled, very carbon coated). I don't know if the fouling was just since the electric choke was put on, or if it's been running rich for the last 3 years (since engine and carb rebuild).

I re-adjusted the carb: choke position, choke plate gaps, pull offs, fast idle, etc. Also, I tried adjusting the air/fuel mixture screws, 3.5 turn out, set with vacuum, but that didn't seem to help much. The smoke is a lot less, but I'm still getting the wet spatter during startup idle. I've got some Berryman cleaner in the fuel tank to help clean up the carbon, but how long should it take? I just don't trust the engine right now.