engine for testing purpouses first. Another good point is if you decided to go that route...you can test the pressure before and after the unit with some type of crude pressure sensor/switch...that way you could know for sure if in fact pressure/temp is being subjective due to the oil feed filter...besides you would have a hell of a time testing that piece with it in the engine bay....something that would be much simpler outside the car. Good luck with that.
BTW- Loved the electric water pump job. Good work. Keep it up.