What is it for ?

[stepsider]

While doing some disassembling on my 72 I found out that it use to be a stick shift. I notice next to the fuse panel there are two relays, The one with two prongs red & green wires. The other one has 4 prongs, This on has 4 prongs 3 regular & 1 a little larger with a square hole in the middle of the of the prong. I'm guessing this could have been V8 or 6 with a stick. On the 4 prong there are noe wires around to fit it ???