1969 Barracuda 340 Formula S Restoration

Was talking about this groove in the inner shaft (on the right) that would be full of nylon. I’m not certain, but I think there may also be a matching groove cut on the inside of the shaft on the left. Seems like that would provide the shear force? Must be someone who has taken these shafts apart and can confirm??3DD62BD1-3F68-4DA3-AD59-EAEC300AEDE6.jpeg