Hi everyone I am new to the forum and could use advice from some seasoned carb builders. I have a 75 Cadillac Coupe Deville, the car has a true 67k miles on it. It sat in a garage from 1979 until October 2013 when I put it on the road. When I got it the previous owner had gotten the carb rebuilt and some how got a chevy 350 carb back instead. I replaced the fuel lines got the fuel tank boiled out, replaced the fuel pump, and tuned it up. It never ran right because of the incorrect carb.
I bought a good used carb from a Cadillac only junkyard. Its a true 75 Coupe Deville Carb. I sent the base plate to a local rebuilder where it was cleaned, checked, and rebushed. I soaked it in chemdip for a few days and then blew it out with compressed air followed by spraying every orifice out with carb cleaner just to be sure everything is clear. Then I rebuilt the main body of the carb. I did a full tune up, replaced all the vacuum lines, turned the mixture screws in until they seated lightly then back them out 2 turns and started the car. It ran rough and idled low. I checked my timing its set to factory specs. I set the idle to 700 and turned the drivers side screw out an 1/8 of a turn and saw the vacuum go up, then I did the passenger side and kept going an 1/8 at a time revving the engine occasionally to clear it out. As the vacuum rose the idle picked up so I set it back down to 700. Finally I got 24 inches of vacuum at 700 rpm but the mixture screws are 4 turns out. I know that's too much for a q jet, not to mention it stinks incredibly rich. Ive checked with a can of carb cleaner and cant find any vacuum leaks, Im not sure what else to do. Can you guys help me out?