For those of you caught in between with regard to putting a 160 or 180 degree thermostat in, I’ve found a 170 degree made by Motorad. It is part number 200-170JV (with jiggle valve) or 200-170 (without jiggle valve). It is in my car so I know it fits. Doing an application search will say it does not fit a 260/289 but I believe that is due to the odd temperature spec. I didn’t notice much of a difference between it and the 160 degree I had in. Maybe 1/2 the width of the needle. Use your own judgment. Got mine on eBay.