Thermostat bolts / threads?

[avguy]

The bolt heads on mine are corroded, so I'm not able to see what's stamped on them. However, I can't imagine anyone replacing the factory bolts with ones that are smaller. Are you certain that the o-ring is completely compressed?

[Nickelbawker]

The bolt heads on mine are corroded, so I'm not able to see what's stamped on them. However, I can't imagine anyone replacing the factory bolts with ones that are smaller. Are you certain that the o-ring is completely compressed?

I tested out what you said today by removing the housing again and putting the bolts in with nothing and they did go in further than with it on. I believe they are correct I see 10.9 bolts elsewhere on the engine but no matter what im not able to attach this thermostat housing so I've ordered new gaskets.

But do you think it's a possibility that my housing could be cheap and need to be modified by changing the the thickness of it a little? It's a metal one that was already on it when I bought it.