have to close choke plate?? to keep car running-why??

I wasnt sure where to post this or how to search for this as I am being vague today lol. Anyway- I have a 360 in a 74 duster. Just put the engine in recently-from a 79 cordoba. Both engine and trans together. I cant figure out why I have to completely close the carb choke plate to get it to run. If I let it open in any way- engine shuts off like your hitting a switch. My guess is a vacuum leak. Thing is- engine ran without a problem in the cordoba. Engine did sit for about 6 months under a tarp-supposedly. Its either huge vacuum leak or maybe floats?? Im not a carb guy, so I am guessing from past experiences. The only thing that was done to engine involving vacuum leaks is that I had to change the throttle and kickdown hold downs and spring hold downs for same. I took a bolt or two out at a time and replaced as I went- didnt loosen whole side of intake at once. Either way- this shouldnt cause a vacuum leak that bad, right? The gasket never seperated. All vacuum lines on car are blocked off-all except for choke diaphragm and pcv valve. It is a 2 bbl carb. Could it be getting too much gas? not enough? vacuum? If I leave the top carb plate open, I have to keep giving the carb shots of gas to keep it running. With choke plate?? closed all the way-it runs good.
Ideas of what it may be and what to do? Things to look for and try?

Tia, John
Ps, car engine is being bypassed from ign switch. No key yet so running with coil pos through toggle switch to batt + and screwdriver to starter relay. Not sure if that changes anything- just trying to give as much info as possible. Still no juice to wiper motor, but have juice at heater blower motor. Going to redo rusty contacts on fuse block.