It looks like it's supposed to be a 160 degree but my question is, does it have a weep hole in the flange of the thermostat or no? I have seen them both ways. (Factory closed cooled)
Re: Which thermostat 88 MIE 5.7L factory 260 Closed cooling
Should be a bleeder hole of some sort, I have seen some with a 1/8 hole,some with a hole with a little valve type doohicky in it. In my closed cooling system I use a automotive 160 thermostat with a 1/8 hole drilled in the flange just clear of the gasket.
Re: Which thermostat 88 MIE 5.7L factory 260 Closed cooling
My drawings show that a 143 degree thermostat should be in. Part# -59137. I also think that a weep hole with a "little valve type doohicky" is the best choice. Allows air to bleed off (for a system fill from empty) but will reduce the amount of cold water hitting a hot head if the system is filled with a warm engine.
