Starer issue after oil pump/oil pan replacement.

My oil pan had some severe rust on it, so I opted to replace it, as well as my oil pump while I had the pan off. I had the vehicle sitting for about a month with no oil in it, so I figured it prudent to prime the system a bit. I then removed the glow plugs, so the starter wouldn't have to fight the engines compression, and removed the pink wire from the IP. As soon as I started it, it made a grind like the starter grinding the flexplate. The starter was just rebuilt, so I removed it to inspect it. No obvious damage to it or the flexplate. The starter bolts were torqued correctly, and the bracket was in place. I have a 27mt, and that rebuild was starting the truck like a rocket prior to removing it. Its also worth mentioning that I have done the Doghead mod, as well as installed a momentary push button for the glow plugs, my control card has been removed. I also have bypassed the resistor bank. Any ideas? I was trying to avoid priming with a drill. I have removed and replaced the starter before with no issue.

Loose wire on the solenoid, failing solenoid, crud or something kept the starting from evening sitting against the block? I'm just throwing ideas out because to me it seems something isn't right with the starter unit itself. Pull it back off and ground test it. Verify the Bendix is moving all the way in the cone and freely.