I happen to have a bare (and only a bare one) lower gt40-style intake manifold. The problem i'm having is as to what goes in 1 of the 2 coolant ports on the rear of the lower intake. All I have is an ACT sensor between the 5 and 6 runners, a coolant temp sender on the front left, and a coolant sensor that screws in the coolant lines comeing out of the front right leading to the heater core - But I am missing something. I am pretty sure the left rear (driver's side) has nothing more than a plug in that passage, who knows what goes on the opposite side (or if I am missing a sender/sensor/plug, or if I have one in the wrong location)?