don't know about a 2.5, but i have the same problem on my 4.0. all the below comments are based on a 4.0.
if it is the same part, i think it is a dealer only item. i have done some research and found that the threads in the water pump housing are standard pipe thread. my plan is not to remove the water pump. remove the old fitting, thread a standard brass pipe fitting in the w/p housing, put a 90* elbow, then a hose barb fitting for the heater hose. the use of all brass fittings, problem solved forever. any hardware store or even lowes/home depot has this stuff.
even if you get the fitting from the dealer, it will happen again.
denton county, tx