Yep! 6x5.5, roughly 26" end to end, and 30 splines.

 

New axle from AZ arrived, bearing is pressed back on, and now I realize why the left and right axle shafts have different part numbers. The bearing retainer nut on the right is right-threaded, while on the left it's left-threaded. Getting back in contact with the seller rn.

 

Finally got the axle, put the bearing on it, and got time to put the whole thing in, only to find that the new axle is too long. It slides in and splines up, but hits the center of the diff with another 6mm (1/4") to go before the axle flange meets up. I only have handheld power tools, so cutting is not really an option. If anyone has any advice, I would love to hear it.

 

Cut it with a disc style grinder......it will be fine to do so.

 

Thanks for the suggestion, homie! It's not the cleanest cut, but it slid and bolted right on in. And I got a cool little coin out of it.