Choke doesn't seem to work as it should
I'm just starting to be able to drive the car after working on it for five months. I know I need to optimize the carb tune at idle. When started cold with no heat in the motor and below 50 degrees outside, it really doesn't want to idle. It fires, runs ok for a few seconds and then starts to surge and die and occasionally backfire. I would assume that I need to apply the choke to keep the rpm up, but that just seems to make it worse and it dies almost immediately. So I leave the choke off and feather it at about 1200 rpm for a while until it will idle on its own at 800-900 rpm. When fully hot the idle is up to 1100 but if I set it lower it will die in gear. When it is up to temp it idles/drives good except for a bog at initial tip in from lower rpm. I'm going to pull the carb off and start from zero but I'm wondering if this issue with the choke is pointing to something specific?? Seems like it already has too much fuel and choke just makes it worse until it heats up. I did initially go through the process of initializing the transition slot coverage and air bleed screws but I don't know where I am now.
Its a 71 340 with headers, stock-ish cam, automatic trans, 13 degrees initial, and a 650 Holley DP, that has been rebuilt by me.