727 shift kit?

It is very sloppy in the valve body support. I'm already using a extra tall seal to move the sealing surface on the shaft. Also machined the shaft smooth (pat Blais) So the play is either valve body or worn lower part of the shaft.

I'm making 420hp (crank) just got a custom built Frank lupo dynamic converter as well. Always seemed to shift well hence my question about checking if a kit was already installed in this trans.

Well then, I guess you will just have to go with what you feel is best on the shaft problem then.
Stock valve bodies can be gotten pretty cheap and easy, but the case is supposed to support that. (unless the case is egged out)
It's normal for the VB end to be somewhat sloppy IIRC.

On the shift kit part:
If it has that HP numbers and a converter one would hope it already has a kit, but the only easy way to tell is if the separator plate is a non OE color (like goldish or red) or it has a non stock manual valve.
On the replacement manual valves in some kits they don't have a gap between the valve and the valve body metal when in park, whereas the stock valve has a gap. (pic below)
Other than that you pretty much have to tear it open to see you can tell if mods have been made.

A missing spring out of, or a blocked accumulator might be a clue, as would any orifice plug in the accumulator oil ports or case ports.

vb.jpg