Poor idle and off-idle performance after distributor swap

Ok so I took the intermediate shaft out, it has significant wear as well where the distributor shaft mates in. They are clearly not seating fully together, looks like just the tip of the distributor shaft is inserting in, and allowing a ton of play. With the 2 parts inserted fully out of the car, they lock up nice and tight. So either the distributor shaft is too short or the intermediate shaft slotted end is sitting too deep inside the gear, not allowing the two to fully mate.

*Edit; I also looked at the old distributor. The shaft was about 0.020" longer, and had nice a nice clean undamaged end. It was inserting just deeply enough into the I-shaft to grab with minimal wobble. The current distributor has more wear on the end and a more pronounced chamfer, so it was barely holding on to the I-shaft.

I ordered a new intermediate shaft from Summit. Hopefully it has a significantly taller/deeper slot and will allow the distributor shaft to seat fully.