New good converter worth it?

The rear end I'm putting in actually has 2.94 gears so I'm planning on getting another 3rd member with 3.91 gears I can swap in when I'm racing.

I checked the stall speed myself and it maxes out at 2600 when I hold the brakes and give it some gas. Also the trans isn't really questionable, like I said it runs and shifts fine except for the 3rd-to-2nd kickdown when I'm hard on the throttle. Anyone know what this might be BTW? I adjusted the bands and it didn't make any difference.