Cooling system question

[Map63Vette]

I recently started the install of a Classic Auto Air A/C system on my 5.7 swap and the way they handle temperature control appears to be via modulating the flow through the heater core with a servo valve that you install on the return line. This got me thinking about the cooling system as a whole, and I'm wondering if I'm asking for trouble or not. I can't say this for 100%, but it sure seems like when the valve is off there is zero flow through it. My concern is, with the thermostat on the engine closed during initial start and warmup, is there any flow in the system now? It's been a while since I had the front cover and thermostat out of the car (it's a 2006 engine with a truck front cover if that makes any difference). Maybe the old original heater core also blocked off flow, but just did it at the box via cables, so I might just be overthinking this. Just wanted to be sure I'm not deadheading my system and potentially causing issues down the road. In my head I was thinking the original heater core was constant flow and the temperature control just modulated airflow between fresh air and air through the core. I know some older engines had bypass hoses to keep coolant circulating through the block when the thermostat was closed, but I didn't know if this was built into the Hemi internally or not.

 

[67Dart273]

I got a bit lost, but the easy answer is, an engine, ANY engine system should work fine regardless of heater flow, or if there even is one. ---a heater.

 

[Map63Vette]

Here's my best 5 minute diagram:

The short version is, in most cooling systems there is always a flow path. When the thermostat is open, the flow path is through the radiator. With the thermostat closed, you can either flow through the heater core or a bypass line (or both). I don't know if the 3G Hemi has a bypass line though, so my concern is whether I have a flow path if the heater core is blocked off. I would guess most modern engines probably have an internal bypass (old engines had both internal and external), but just wanted to be sure before I ran my car too much.