I would hate to start a new thread for basically the same questions, so...

I just hooked up the electrical to my engine and started it for the first time since installing it (not rebuilt). I filled the rad with water and opened the drain with a hose running in the filler as my manual suggested. My concern is... Whether or not the engine has prime in the coolant system. I may be over-worrying, but now I'm wondering if maybe I put the thermostat in upside down or something stupid like that.

I took out the large bolt under the thermostat and water drained our immediately, and the radiator level dropped. I'm assuming with the thermostat closed, and that bolt being below it, the water would be circulating through the bottom rad hose and out the thermostat, rather than draining backwards from the upper rad hose. In theory, the entire system should be primed then.

I'm nervous to wait on the thermostat to open when I'm uncertain the head is full...

Any advice is welcome.

She runs, thermostat opened, guage works, all is well.