Dan, you've got a problem with the starter gear not dis-engaging with the ring gear. The problem is due to the starter not being correctly adjusted horiziontally for the throw out gear plung in relation to the ring gear. You should not need to apply power the throw out gear.
It's been 15 years since I had to do this, so take everything I say with a grain of salt! try the following:
1. Remove lower flywheel housing cover.
Rule of thumb:
Shimming both bolt holes = increase gap.
Half Shim the outer bolt hole = decrease the gap.
2. Put a long screwdriver into the hole at the bottom of the Starter housing.
3. You should be able to move the Starter gear out so it engages the flywheel.
4. For measuring the gap use an ordinary paper clip. A paper-clip is about .035" thick, and the GM Starter dimension for the mesh between the two gears is: .020" to .060." So, a paper-clip lays right in the middle... It's a perfect tool and you don't have to buy it from GM! And the same tool can engage the Trouble Codes. Ain't it great to be Cheap! [img]/wwwthreads_images/icons/smile.gif[/img] Aaron (TR) advocates using a 1/8" drill bit to set the gear spacing. This works for me too!
4. After making the first adjustment, mark the flywheel tooth... nail polish works well. This is so you can come back to the same tooth again!
5. Rotate the engine 120 degrees. Recheck the gap, mark this flywheel tooth.
6. Repeate step 6.
7. Make sure at each 120 degree rotaton you have the proper gap. You may have to split the difference between the gaps at the different rotations. Just make sure the gaps are in tollerance.
8. If you can provide power to the Starter, power up the Starter and rotate the engine a couple of times.
9. Repeat steps 4 - 8 a copule more times.
Let us know the results.