I had ordered for build a 54 Max and a 58 Max wedge with KBS Tour 90 shafts.  I was told today that the shafts are no longer made though at order told they would arrive late June.  What is the closest comparable steel shaft to the KBS 90?  Thank you.

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Duffer Selected answer as best June 14, 2022

0.370 was what I tried to order.