bcowanwheels,
The engine is a 1974 Chevy 250 inline. The engine is in the factory position, the radiator is stock with a "corner fill" that puts the fill cap lower than the top of the radiator, lower than the top radiator hose inlet, and lower than the thermostat housing. The over flow bottle is in the stock position lower than the top of the radiator.

Yes Mr. Stock 49, how does one fill such a system in the first place?

regards,
ken