I have a 650 cfm spreadbore Holley on a 340 Demon and has a divorced choke (don't know what that means) when I physically close the choke the car really smokes and coughs when it starts...why?Thanks Moparts

""when I physically close the choke the car really smokes and coughs when it starts...why?""

Black smoke would indicate that the choke plate is closed too far. The choke plate limits the air into the carb which equals richer which equals black smoke.
Adjust your choke linkage to allow a larger air gap when the choke is applied, or don't close the choke all the way in warmer outside temps. This will allow more air into the carb. The colder the outside temps the more you want to close the choke plate.

Actually, that's exactly what was happening when the flap was completely closed. The main issue is I have an NOS '71 choke (spring action) for a Thermoquad and running a Holley carb. I should make a new arm to allow it to work. Thanks

A divorced choke means that the thermostat itself is seperated (it's in a well in the intake). A ballpark baseline is to adj it to have the choke plate lightly closed all the way @ 70 deg F then when it starts the choke pulloff must immediately open it a bit(eng vac pulls it open some) then the thermostat opens it up the rest of the way as it warms up