Need Help Identifying Giant 2A163 Caterpillar Nut - What Does It Fit???

Greetings everybody, just last weekend I stumbled across this vintage Caterpillar Parts box, as you can see from the pictures it's relatively large.  On the side it has "Quan. 2, Part No. 2A163, Name: Nut" printed on the cardboard. There is what appears to be a date of "5-50" on the cardboard manufacturer's label on the bottom of the box and somebody wrote "65 lbs" (roughly 30 kilos) on the shipping tag.  I looked the 2A163 part number up in one of my old Caterpillar price listing books from 1969 and that nut cost $68 back then, so no doubt it was a very large piece.  It might be a long shot, but I'm hoping somebody can help me determine what Caterpillar machine those two giant 32-pound nuts would've went on??? Thanks in advance!

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Sprocket adjusting nut/s for D8 2U.

Squatch,
I believe what you have there is a nut out of the final drive assembly on a caterpillar D8.

Greetings from Australia, I've been a viewer of your YouTube channel for some time. It's great to see the things you and your father get up to.

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Thank you OM and D8Dude! I appreciate the help - mystery solved!

It also fits the 14A and 15A D8s.