The only difference between the old and new pumps is the old one has a lid, the new one doesn't. The early pumps could overheat on long journeys, especially if the fuel level is 1/4 or lower.
You could fire the parts cannon at the car and replace it, but it makes sense to buy a cheap fuel pressure tester from Amazon and see what pressure you're seeing when you open the door, and/or pulsing the ignition a few times.
I'm pretty sure the engine starts and runs from the in-tank pump only until the ECU commands high pressure from the mechanical pump, therefore there can be a few seconds of crap running if the in-tank is on it's way out. The high pressure pump can't be outruled either.
