[MagmaJct]

I'm impressed that no one has asked one key question:

Does it over heat with high speed driving or low speed driving. This is critical. If the fan shroud is missing the cooling fan is almost completely useless and it'll pull air from the space between the fan and the radiator.

The shroud forces the air to be pulled through the radiator at low speeds (when the fan does most of its work.)

Also, this is further proof that removing the thermostat, or running with a cooler thermostat doesn't prevent over heating. The thermostat sets the minimum coolant temperature, not the maximum. All a thermostat does is prevent the cooling system from functioning until a minimum operating temperature is met, then it "turns it on" so to speak.

If the cooling system is broken, it doesn't matter when it's "turned on". My advice? Re-install the shroud, find a way, then see what happens. If the problem isn't solved, don't think the shroud wasn't the problem, look at it as a "contributing factor" that has been eliminated. Details matter!