How do you get the thermostat to open?

[nick]

I've tested my brand new, 189 degrees F thermostat in hot water. It opens perfectly.

I install it in my 83 d24t, and I just can't get the thing to open. Both ends of my head will be around 210 degrees F, while the thermostat housing is only at 140 degrees F. The top portion of my radiator is 175 degrees, while the lower portion and lower hose are not even 100 degrees. I've spent over 10 hrs trying to bleed air out of the system and get the water to flow.

I'm driving around with no thermostat since I can't seem to get mine to open. I even tried drilling a couple holes in a different working thermostat and installed the thermostat orienting the holes towards the top of the bore for water/air to flow. It still won't open.

I've never experienced so much trouble with a thermostat on any vehicle. Any advice?