Just had a thought Meller... "ouch"..
Maybe you mentioned this before and I missed it but, how are you arriving at the decision that the car is running hot? Is it puking coolant? Or is there a gauge that says this is so?

If it is just a gauge.. how confident are you in that gauge? Do you have or can you borrow another gauge / thermometer / infrared temperature meter? Maybe if you don't have one, you might know someone with one???

I like using the infrared "gun" as you can measure the top and bottom temps right at the hoses..

Anyways, just a thought, if it ain't puking each and everytime and/or the gauge shows it's hot, it may be a good idea to just cross check the gauge before you decide to spend some monies.. fwiw, my 2 cents, imho... etc. etc. etc.... 8-)