This is on import (4G63) motors, but when I concrete a block,, they'll pop a freeze plug on the (aluminum) head and run a line (-16, I believe) directly to it. Usually a solid copper head gasket that has been made specifically for a dry-decked block (coolant cut-outs have been deleted). IIRC the thermostat is on the back of the head, so that acts as the exit.
So yeah, you'd need to figure out where's a good spot to have both an inlet and outlet for the water.
Also, don't fill the heads, especially if it's going to be running for more than 30-45 seconds. Things will start warping.
88GT with the 5.slow