I just changed all the wiring harness in my 1970 chevelle SS 396, I am left with two plugs by the back of the distributor on the fire wall. One looks like an S and the other one is straight. I looked in the factory assembly manual and it looks like there should be a T.C.S. Relay on the fire wall. Does any one know what these plugs are for and what does the T.C.S. relay do ?