what is behind the thermostat housing leading to the valley of the block?(83k) on 2004 Ford Thunderbird

there is a cooling leak from what appears to be the water pump. replaced the water pump. pressure tested (2 psi) and something is still leaking into the valley to the back of the block. theres a small trail from what appears to be the piping from behind the thermostat that leads to the valley. im unable to see without removing the entire intake.

Asked by for the 2004 Ford Thunderbird