i Doubt it is a fuel issue unless it is the float. There is enough gas in the line on a carbed engine for it to run for a while. It would be a bigger issue with injection. If the floats look ok, I would look for a wire that could be moving, getting pulled etc when you turn. Do you loose all power to everything. I think those Mustangs used to have a harness issue in or near the radiator support.
Artificial Intelligence is no match for Natural Stupidity