Looking closer, the black / yellow wire was on the starter as it should have been. The disconnected black / white wire was dirty, and just looked yellow.

In any case, got the three wire starter hooked back up, hooked the black / white wire hooked up to the third wire on the starter. Went to fire it up... now it just grinds more vigorously. So def more power. Just not mating with the flexplate...

*sigh*