OK, I finally got the wires off and here is what I have.  First of all, I have an MSD distributor and 6A ignition box.  The wire bundle going to the starter has 3 red wires.  No purple wire.  It looks like the factory wires because they are all cloth wrapped and come out of the larger cloth wrapped harness.  One is a large hole terminal that I assume goes to the large terminal along with the positive battery cable.  Of the other two one is a small gauge red wire and the other is a medium gauge wire.  My fuse link has a red wire going into it and a red wire going out of it, not dark brown like the wiring diagram says.  No yellow wire from the dist., but thats probably because of the MSD stuff which I didn't install.  I also have a black wire coming out of the wire bundle with a large hole terminal on it.  Is this a ground?  Should I just put it on one of the starter mounting bolts?  So should the small gauge red wire go on the motor side of the solenoid, which I think is the S terminal?  And what of the other medium gauge red wire?  The R side? 

Black wire/large eyelet is gonna be a ground. Bolt it up to the bellhousing or starter bolt, whichever is closest.

On the two red wires, see which one has 12v when you turn the key to "Start"...that one goes to the terminal closest to the block on the solenoid.
The only other small wire down there would be for the ign "Start" voltage. I'd go ahead and hook it up, to the outer terminal on the solenoid, whether the MSD uses it or not...

It's strange that you don't see/have the burple "Start" wire....I can't ever remember seeing a Chebby that doesn't use a burple wire for that....

One of the permanent truths of Chevrolets is that the PURPLE wire is the start wire, and the 74 wiring diagram confirms that.  Apparently someone has done a professional looking job of replacing those wires.  Joel is exactly right about checking for 12 volts with the key on start.

Larry

Ok, I found out which wire had 12 v with the key in start and hooked it up to the S terminal next to the block and the other to the R terminal.  I think where I went wrong was hooking up the black wire to the starter terminal.  It is now on a starter mount bolt for a ground.  The car starts normal and the a/c and blower motor work normal, so that was my problem.  But, my wipers still don't work.  I've tried the park knob under the dash, and the fuse is good.  They are stuck just out of park, so the door can't close. 

Ok, I took the wiper door and louvered grill off and when I jiggled the rod that opens the door, the wipers retracted.  Vacuum is not a problem as I can open the headlights or the wiper door with the pull down switches under the dash.  When I turn on the wiper switch I hear a click but the wiper motor won't run.  I have disconnected the wiper linkage from the wiper motor.  I guess I'll have to remove the wiper motor and take it apart.

I can offer no help here but would like to say I know how you feel. I started with a simple seat swap and ended up in a whole heap of crap!

Thanks for feelin'  my pain.  Sometimes this hobby can be a PITA.

Upon further diagnosis, if I open the wiper door manually with the switch under the dash, the wipers don't work but it does work if I push it in the washer position.  I do hear a click when I try to turn on the wiper switch but nothing happens.  With the door closed, the wiper switch will not open the door.  Neither does the washer position.  Could it be the wiper electrical solenoid?  If so, where is it?