Ok I am putting a 90 350 in my chevelle, and I had to buy a new starter for the larger flexplate.  The new starter has only one small post and one large one where the older starter had two small posts.  Do I run both wires on the one post or what so I do here I need to drive my car.  

Big question is what year is your Chevelle?  I just ran into this last night when my new gear reduction starter got here.  In the older point type cars, the points and condenser did not run on a full 12 Volts.  They ran off of eight.  Some cars had resistance wire, and others had ballast resisters for running after the engine started.  The one wire going to the starter is a bypass to give the ignition system a full 12 volts for starting.  My new starter instructed that if the car is running an electronic ignition system, the 8 volt requirement is moot - so the one wire running from the starter to the ignition can just be capped off.  If it is intertied it told how to hook the two wires together and put the bypass wire on a resister of a certian rating.  If you discover that your ignition is intertied, what will happen is that the starter may not work.  Another simpler solution that was also suggested with my starter is to get a two pole solonoid - either one pole or two pole should work on the starter all other things equal.  In my case, I know the ignition is not intertied on my car ('67 Cutlass) and I am running an after market distributor - so I am going to just eliminate the bypass wire and tie it off at the starter end.  Good Luck - Bowser  

Thanks yeah the chevelle is a 69, I got it worked out the one without the fusable link is the reduction one to protect the balist resistor in the old school starter, so I wrapped it bck and taped the whole section for a nice clean look.  Thanks for looking out for me.  Oh and yeah my ignition is aftermarket as well, so all of that has been switched over without destroying the old in case some of the Auction guys run out of good stock to peddle.  

This is an old 'holdover" from when Chevy's had points in the distributors. As you know, they used a resistor to cut down voltage/current to the points and therefore the coils this was to help prevent premature point failure and to keep the coil and points running cooler.
Now when you want to start the car the coil needs a lot more voltage to make up for the draw on the system from the starter. Therefore the 'extra' contact on the starter solenoid was to 'bypass' the resistor and run full 12 volts to the coil.