There is a screw behind the choke, facing towards the front of the car, on the passenger side of the carb that adjusts the choke release. My guess is the previous owner screwed it in to tight and it's "stuck" in a groove it created since the cam it rides against is plastic. Also your idle adjustment (driver side near the base plate on the carb) might be set to high. You can turn the screw counterclockwise and see if the throttle bracket rotates back towards the firewall. Your timing could be to far advanced also. Personally I would back the choke screw off so the choke won't stay on long (is it electric or a mechanical choke). Once this happens slowly tighten the screw until you get to a point you can live with. Also check for binding of the choke butterfly. I would than back off the idle adjustment screw until the throttle bracket on the driver side of the carb doesn't move anymore. If you car dies than slowly turn the screw back in until you get an acceptable idle with the car in Drive (with brakes on of course). Ideally you should pull the carb and verify where the primary butterflies are in relation to the transition slot but that is a whole new can of worms. The stuff listed above should get you started and it only requires a screwdriver (except removing the carb).
