Where to find the no-spin for the eaton HO52?

[UMDSmith]

I have the eaton HO52 rear with 4.10 gears in my 70 C20. I'd rather not do the rear end swap to a corporate 12 bolt, though I will if necessary.

Does anyone know (besides maybe a junk yard) if there is a way to get posi-traction back into an HO52 from either new parts or a used source?

This truck is my winter DD for inclement weather, and I'd prefer more than 1 wheel drive.

[hammerholley]

I hear you can put in lunchbox style locker from the 14 bolt but i have not done this yet.
i would like to know more because 14 bolts are in the yard round here.
Just finished disc swap in rear ho52 4.57