So I had to figure the best place to drill the second hole on the firewall angle. I loosened the arm on the butterfly valve because it was just going to be in the wrong location. I played with the arm on the valve and changed angles of the oil cooler until I felt I had the best position that would accomodate both to my liking. Too much an angle would cause the arm to hit the engine mount; not enough angle would cause the plenum to not have clear access to place the hose on it because of the engine mount once again!
I took my time and changed angles and drew lines on the firewall with arrows and marks......I think if I would have kept it up a little longer I would have discovered the theory for time travel!!!
I marked the center of the angle using the center of the rivet line...pulled the angle off and drilled the bolt hole in place. I reinstalled the angle and match drilled the hole on the rivet line. With that hole drilled I established the angle and position of the oil cooler and could work on the front supports.