Another note not mentioned for the 603 is that the aux fan is regulated by a thermo switch and the aux fan should come on at 105c.

My 87 300D will run hotter in the summer heat, and with AC on too. On the hottest days, I've never seen my temp guage go past 90c, but I've never climbed a mountain under those conditions either. Also make sure your clutch fan is not shot, give it a spin, there should be resistance and you cannot make it spin a full revolution on it's own by giving it a whirl with your finger (engine off of course) ....BB