i have a 94 250 4x4 with the 7.3 turbo (not power stroke )
was driving fine then began to miss and shake and smoke like a train (black Smoke)
any thoughts on this one truck has been well maintained and only 174k on motor

Heres a few things to check: Could be a turbo bearing going out, if its not spinning as fast as it should, it can cause a restriction in the exhaust causing similar problems. Also the injector pump bypass can become restricted, actually causing the engine to flood at lower rpm. Theres a fitting on top of the pump that has a check valve in it that can stick, or become partially clogged. Take the line off of it , and see if you have good flow. You can drill the check valve out to see if that solves the problem, and replace it later, but it will run fine like that. Ive had to do this many times for emergency , side of the road repairs to get someone going. Sometimes it is the return line going back to the tank. Good luck.
Later
Ed