Originally Posted by David.X5

I've done this on my 2001 4.4i. Pretty much twice. Once when I pulled the engine and the second time when the crossover pipes were leaking.

I think you are better off removing the water pump and working from the front. It is technically possible to remove the cross over pipes after removing that rear distribution piece, but access stinks.

I recall the valley pan has a gasket integrated into the metal part. I replaced the entire thing. I recommend replacing the two crossover pipes while you are at it - they corrode around the orings - I tried a little sanding and polishing but had a slow leak there within a few months. Of course, mission creep is bad on this job. It would make sense to replace the water pump and thermostat housing while you are in there and the fan clutch and some hoses and ... And ...and ...