Going to replace the upper hose and full thermostat housing and want replace the studs that going into the block as well since the look kind of corroded, does anyone know what size they are? Could not find it via forum search. It is the 2 studs that connect the junction (not sure if that is properly term) to the block.

 

If i understand it correctly you are talking about the 2 studs that are a part of the water pump housing which is connected to the engine block.

The size of these studs are M8.