MRXR8D doesnt have a header tank...he has an au? thermostat housing, and an overflow bottle beside the radiator? Does anyone know how effective a system like that would be? Ive gotta move my header tank, saw that, and started thinking i could do the same on a EB 5.0?

well..... they used the same system for years, all the overflow tank allows for is to keep the radiator full of coolant, with a header tank, the coolant expands when its hot, the air in the header tank gets blown out at pressure, and air gets sucked back in when the cooling system cools down, but the radiator also stays full of coolant..... bit more foolproof than a sealed/recovery system with a overflow bottle, particularly as you can see your coolant level without any effort

the other side of having a header tank is where the radiator isnt highest point in the cooling system, therefore the header tank becomes a substiture bleeder.....

Is this the blue EF XR8 with the terracotta interior that was featured in Street Fords magazine a while back?

The filler cap is on the thermostat housing, which is the highest part of the cooling system if you take away the header tank.

I don't think it's an AU thermostat housing, if it is, it's been modified to fit the cap on there.