[chevymad]

I went through 3 of those same thermostat housings before i gave up. Each lasted about a year. They all leaked. They'd corrode clear through past the o-ring. Only thing in the whole cooling system that showed anything like that. Flushed and new fill each time. Original radiator and everything else. Finally give up and bought an iron replacement. No more problems. I think its just a cheap material they make them out of.