1978 stock corvette 350 4-speed with Rochester quadrajet 17058211. Carb was rebuilt a year and a half ago. My turn to work on the car... Car will not idle below 1800 rpm. Rpm does tend to surge but eventually stalls. I do see some nozzle drip. Car will start out at high rpm and slowly the rpm goes away until car eventually stalls. With a couple pumps of the gas it starts right up and then starts all over again. I have verified that it is definitely a carb problem as I swapped the carb with an identical know good working carb and car ran great. I have since replaced gaskets, needle and seat and cleaned with carb clean, but did not tank the carburetor. Could this be caused by leaking bottom plugs? Also, idle mixture screws have no effect on engine rpm. I put a straight edge on the body of the carburetor and there is a slight warpage. -Jon