hey! not that it matters now, but napa likely has a thermostat in stock for 1987 ford ranger 2.3L turbodiesel, available in different temperatures, but where i am is real cold in the winter, maine gets cold too i hear - get a 195F thermostat, and keep your cooler one, likely a stock 160F for the summer. i bought mine from 'parts source', a subsidiary of canadian tire doing competition with napa, cost me $11. way better than the price for OEM thermostat at $35+!

1953 Willys CJ3A awaiting Buick V6 Fireball and auto trans.
1987 LWB Samurai JX rustbucket