Bolt Size CV to Diff?

Can one of the technical experts tell me this bolt type, I stripped the allen head, thankfully not enough to prevent its removal. It attaches the CV joint to the diff hub, I am doing the other leaking hub seal.

It is 65mm long, 10mm diamter and 1.25 thread pitch, takes an 8mm socket. Is it a grade 8 or is there a higher grade for this high torque application, I can't quite decipher the marks on the head? I want to source one locally, and avoid ship costs from the usual suppliers.
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Thank you for the response. I think the bolt will need to be 65mm, or else it will stick out too far and not clear the differential just behind the collar where the bolt nut attaches. Looks like 65mm is not as common a size, in the fine 1.25 thread requirement.

I am not sure why they used allen socket bolts rather than conventional hex head bolts. Maybe the round head on the socket bolt would be less prone to tear the boot when removing the bolts, that's all I can think of. Given the high torque, the allen head stripping seem inevitable, and that is on my bolts that have no corrosion and have been taken off previously.

I think the need for the universal joint on the extensions to get at these means the opportunity to not be fully square in the socket is the problem.

 

Oh oh, I ordered from Superformance, is not the 70mm too long? Original measures 65mm, below the head to the end. Is this not the standard for bolt length measurement? Or do you measure 70mm total length?

Thanks for confirming the grade.