... spark shower
Just a couple of other things...
You may find it easier to disconnect the wires from the starter/solenoid terminal while the starter is mounted to the block, if you can get to them. You may also want to remove the bell housing cover to check the starter-to-flywheel clearance after you replace it. GM recommends 0.020 to 0.060. A standard paper clip works well as a gauge since it's about 0.035. Use shims if need be to obtain the proper clearance. It's not too bad of a job. Good luck.