I am in the process of replacing the water pump impeller on my 76 X1/9 (1300 motor, no AC), and have run into a problem. I removed the four bolts holding the impeller, but it cannot be pulled out of the pump housing, due to the (non-removable) pulley hitting the chassis well before the impeller can be removed. I saw that I had to remove the pump housing along with the impeller. It is held on with four bolts, but the one in the lower left (7:00 position) cannot be reached with a socket or wrench. It appears that I would have to remove the entire exhaust manifold to get to it. What am I missing? I have several manuals for the car, and none of them mention having to do this.