727 Build for Mid-10s

Another question -

These are the two input shaft/hub assemblies I've got to choose from. The left one has a pretty pronounced groove cut into the splines (left arrow). After inspecting the clutch assembly, one of the clutches was completely burned and bare of any friction material. This overheated and warped the steel that was against it, which wore the groove in the hub.

The one on the right has nicer splines, but the shaft has some rust pitting, which I'd imagine would compromise the strength of the shaft.

Which one would you choose???

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