GM starter question

I have a small block chevy starter and a ballast wire that the instructions say to connect to one pole on the starter. Any body know which one and the reason for that particular pole? THANKS IN ADVANCE!

 

Outbord small stud, gives full voltage to the coil for starting.

 

the one marked R for resistor...the other one is marked S for start or something.

 

Correct. Small terminal closest to block is marked S, this wire comes from the starter terminal on the ignition switch and is hot when the key is turned to start. This engages the solenoid. The small terminal on the outside is marked I for ignition, wire goes from this terminal to + terminal on coil. Feeds full voltage to coil when starter is engaged and sucking lots of amps.