87 chevy v20 silverado 4 speed manual 6.2l with just over 950000 orig miles. From ny so dont drive the truck in the winter, needs a new paint job. Question I have to repair the radiator due to corrosion leaks. Going to replace the thermostat but cant find what the original thermostat opening temperature was used. I've looked all over the internet but cant find a straight answer. the p/n 14077122 is all i can find stamped on the thermostat and when i look at ordering it online,depending on the mfg that p/n will cross reference to other thermos with opening temps anywhere from 160 degrees to 190 degrees and i would like to know what the original opening temp thermostat came with the engine and what mfg replacement is recommended. Appreciate any help.