Sorry to bring up an old topic but I have read the NP246 32 spline input shaft swap thread about a million times and am at a dead end.

I purchased the input shaft from cobra transmissions PN 391670 (19019) and it just barely doesnt fit into the planet. My stock 27 spline fits easily and they look almost identical in diameter and outer gear cut.

Has anyone experienced this issue? I tried working with cobra but they said I needed a different planet. The only difference I see is on the outside gear the teeth seem to be slightly thicker as compared to the teeth on the outside of the 27 spline shaft.