The bendix is definitely popping out and into the flywheel, but it's jamming up and not syncing. I didn't think I'd have to shim anything, but the instructions that came with the starter indicate otherwise. Shimming didn't help anyway. I spent the rest of my Sunday pulling off the headers and yanking it out. I'll bench test it to see if it's working properly, but I'm pretty sure it is. With the rest of my Sunday, I took apart the old starter, cleaned it, measured the resistance on every connection, regreased the bearings and reassembled it. It spun up nicely after that, it may be going back in instead.