1969 C50 thermostat

[Mark-Ia]

Can someone verify where the thermostat goes in this 1969 Chevy C50. In the manifold or below the top housing for the radiator hose? Engine heats up very quickly. Head gaskets were replaced and heads surfaced and checked for cracks.

 

[rustred]

, the top housing is called the thermostat housing , right under it.

 

[Mule Meat]

As Rusted said.
You must remove the two bolts that hold the thermostat housing (radiator hose attached) to the block.

The thermostat spring should face down when installed properly and sit into a small recess machined into the block. If it isn't you stand a good chance of cracking the housing when you tighten the bolts.

 

[wore out]

Can someone verify where the thermostat goes in this 1969 Chevy C50. In the manifold or below the top housing for the radiator hose? Engine heats up very quickly. Head gaskets were replaced and heads surfaced and checked for cracks.

As the others said the t-stat goes on top of the coolant bypass block, under the coolant outlet fitting.

That external bypass fitting allows coolant to rapidly recirculate through the block preventing "hot spots" when the t-stat is closed and not allowing coolant circulation through the radiator and was a factory add-on when those engines were used in MD trucks.