Mini Starters on a Slant Six

H'mmm. This is not the starter I would pick; I would go with the standard Chrysler mini starter retrofitted with a 9-tooth pinion. Reason: the Chrysler mini starter has a nose cone which fits into a recess in the bellhousing fix the location of starter relative to the ring gear, much more precisely than just the bolts holding on this no-nose starter.

Also, my way would be a lot less expensive.

On the other hand, it looks like this starter will accept the "seal" (shim plate) from your original direct-drive starter, so there's that.