I haven't "filled" it, but I did fill it a bit beyond half. Now that u mention it, after the boiling and the overflowing, I ran it up to temp and parked a few times (I only live a mile or so from work) my coolant level is is at "half full bottle".
I'm really considering a cooling conversion. This is aggravating.
I flushed the system with off the shelf prestone product twice and the water flowing out of the radiator hose didn't seem restricted to me. When I changed the tstat, the water jacket behind the tstat on the head and tstat housing looked really good so I imagine the radiator passages were cleaned well enough. But I'm no pro in that area.
Rev. Toid