[Mopho]

When I blew my rear plastic fitting and the water pump, ended up being from the lower radiator hose leaking and blowing the head gasket. Being a M-44, the rear fitting was totally destroyed and came apart in pieces, my mechanic told me when he took the head off part of the rear fitting was still in the head and he had to dig it out. So my plastic fittings along with the front one, were replaced along with the water pump I had already replaced...
I think if you do anything to the cooling system, all of these parts should be replaced to save time, labor and money including the radiator (my 96 ti had about 145,000 miles on it when the lower hose that had been replaced wrong blew).