I have run a 180 for the last 2 tears. Downside is swamping at a short stop. Will go to 200 indicated, and it takes for ever to get it to cool down. This is in summer and with a new radiator. So I am thinking about a 160 just to give a bit of a cushion to the recovery. The truck does not like the higher temp. It will surge and Idle rough until it cools. 235 in a 52 1/2 ton and here in Utah with a lot of 90 degree days. It is my daily driver so it sees, rain and snow, but I do avoid the slippery stuff as much as I can. If I were to do it again, I would use the water pump relocation plate and move the fan up to the center of the Radiator. It has to work better in the right place.
I am willing to bet my entire collection of salvaged clutch head screws (I am queer about them, BTW) that your over-heating problem is the water pump/fan location. Way too many people going through the trouble and expense of making that mod for it to be unnecessary.
Carl
