I hate answering questions when I know I might be wrong but the float level was the first thing I thought of to. I have to agree on the float level theory even if the carb was just rebuilt. I'm definitely not a Detroit Carburetor export, I've never rebuilt one, but I've rebuilt hundreds of carburetors at work, and they all basically work the same way. I wondered if it could be the float, especially a brass float, they will get a pin hole in them, absorb fuel and will sink. If you rebuilt a carburetor that had been sitting for a long time, there might not be any fuel in the leaking float, it could have dried out but then once it was put into service it slowly filled up the inside the float with gas and it would start to sink. I saw that a lot on the carbs with brass floats. If the float okay, then I'd double check the float settings and adjust air fuel ratio. The carb may not be the problem but unless I rebuilt the carb myself and verified the float level, the condition of the float, all the internal passages were open... that would be where I would first look. The carb may have already been done by a good rebuilder, but I have no way of knowing that. When you say it stalls while turning that leaves room for a couple possibilities. It helps if you can tell if it's loading up on gas, running out of gas or did it just instantly shut off like the key was turned off. If it dies going around a corner how it restarts can help you solve the problem. Don't modify a thing, that just makes it an even bigger mess.
If it's not the carburetor, then you could check the wiring to the ignition system, make sure you have tight connections, and the wirings insulation is all good. Maybe wiggle the wires while from the ignition switch to the coil and see if it has any effect on it.