1992 E150 351 windsor, every now and then the engine shuts down for a split second, I have heard this is somewhat common for the ECM, is there a cure such as aftermarket ECM or modification to factory ECM ?
What is causing it ?

 

Could be a lot of quests on what's causing this.......

Several sensors could cause this, like the MAP sensor.

Also, you can check the ECU by pulling it out, open the case and check the capacitors on the circuit board, if the capacitors are leaking green junk, then there bad. They can be replaced, or a new after market ECM that is flashed for your engine/transmission can be ordered and replaced.

You might want to check this Link for other suggestions.