[HO455]

Good catch Geezer#99 on the heat riser. The lack of heat to the exhaust crossover will not allow the clutch spring to have full range of movement.
Going with an electric choke set up, reopening the heat riser, or going manual are your best options. If you go with one of the first two there will be a choke set up period to get it dialed in.
When I set up a choke, I do as stated above making sure the choke blade is closed after setting the choke by pushing the throttle down 2/3rds to the floor. (This should also provide a shot of fuel from the accelerator pump.) Then the choke blades are opened by the choke pull off about 1/4 inch when the engine starts. You can use a vacuum tester to set the opening.
When starting the engine the fully closed choke blade allows extra fuel to be drawn out of the float bowl. When the engine first starts firing vacuum is created and the pull off starts opening the choke blades allowing more air through the primaries and the extra fuel flow from the float bowl stops. Once the engine starts this opening determines how well the engine runs above idle. As the temperature at the exhaust crossover rises the choke blades are opened. Most electric chokes make their own heat and open in relation to the amount of time the ignition has been energized. The other style of electric choke coils have a bolt on sensor that controls the speed of opening. Years ago I ran one and it was one of the best chokes for a Qjet I have used. The problem is that I haven't seen that style for sale in a long while.
The idle speed is boosted by the fast idle cam. I shoot for idle speed about 1200 -1500 when the temperature is down below 50 degrees. There are several steps on the fast idle cam and at about 50 degrees you should be on the lowest step. As the temperature gets colder the choke coil should pull the cam farther to the larger steps.
If the engine stumbles coming off idle then try opening the choke blades 1/8" more if that makes it worse then close the blades a 1/16" from the original 1/4" setting. It will take several tries to get this right.
Once the original set up has been tested and found to be mechanically sound I park the truck overnight and in the morning I drive to work and decide if I am happy with the setting. If I'm not satisfied I will make an adjustment before leaving work. That gives me the trip home and back to work (2 cold starts) to decide if I like the setting. I repeat this process until it is running like a new car does when cold. As stated above it is a balancing act to get it set. Back in the day a good shop would set it and then keep the car for a day or two to make sure it was right. Letting the car cool completely each time is important.

I hope this doesn't cause any confusion.