Here is what is going on:

Original starter (when I got the car, probably not the stock one) would more often then not, take a couple tries to starter. There would be a loud click, and I'd have to let off the key for a second, try again, sometimes it would take longer then other, but it would always start before long. Heat killed that starter....

New starter... clicks all the time, won't start anymore. Shims only make it worse. The nose gear is hitting the flywheel, which is most of the loud click. I tried to shim it like this: Tried both the shims included w/ the starter, one thick one, one thin one. It starts, but takes a few times. Drive it home with that. Trying to get rid of the annoying click, so I take out the shims, cut the thick one into thirds. Tried one thick one on the inside bolt, doesn't want to starter. Try two, stops clicking, but it makes horrible noises. Okay... three on the inside... nope, makes horrible whining as it barely touches the flywheel (I think). Okay.... try thin shims.... two thin shims on the inside, doesn't start. Try a thick shim on the inside and two thin shims on the inside... tried to start once, but turned over very slow and makes loud noises...

The starter is a Wilson, part number 10455012... the car is a 1991 Firebird GTA, 305 TPI.

Did I get some crap starter? I really want my car to run....

Thanks,
Douglas

 

Your problem may not be the center to center distance of the gears (which would be controlled by the customary shims) but the depth of the drive pinion. You can adjust the pinion depth by the thickness of the lock ring/shim at the nose of the starter, which controls the starter motor shaft position in the housing: