Hi there. I'm at work and do not have any of the cars near me at the moment but it sounds like you are referring to the distribution terminal that is equipped on some, but not all, GM cars. I can't recall what a 69 normally has but typically on a normal setup there are only two main wires. The wire from ignition switch for the solenoid which usually goes to the small stud with "S" on it usually in purple for GM cars. And then, the other thick gauge wire that goes to the battery positive.
On some cars GM did use the larger starter lug as a power distribution terminal, so you often find some extra wires connected there, with fusible links. I remember that on an old C10 truck I had where the large lug provides the primary power to the fusebox and also the connection to the alternator to charge the battery. If that is the case for your application, just run the hot wire to the big stud and the ignition to the smaller one (assuming I understood your question).
I'm sure others will chime in but I will try to better confirm this evening if I can get over to where my cars are.