help me identify these 4 speeds!

Don't use the B-body in an A-body. Just trade it for an A-body. The B-body guys can use this stuff. They will be happy to swap you, and you'll get a much easier install. Did I say MUCH easier install.
Also there was no HD 23 spline. There is a 23 spline, and an OD. Any A-body 4-speed you get will be plenty heavy duty unless you go racing. Then I'd forget the 23 spline and go Hemi.