Oil Sender
#2
Is the intake off? It should be an easy swap with it off. Doesn't take very long to take it off after you've done it a couple of times. I can't imagine doing it with it still on, I could be wrong though.
#5
i put a new oil pressure sending unit in with the manifold on. You need an Oil pressure socket.. get one from Autozone. its a tight fit back there, but doable. better than spending time removing and installing the intake