Echobit torque specs.... and I got a BUNCH of nuts

[78Suburban]

I'm gonna take some junky nuts off the echobit flip, I used them because it was all I had, and they're fine for holding it together temporaryily, and might have been fine if I left them forever. Yesterday I bought a bag of 25 all metal top lock, lock nuts, 9/16 size. I figure if I torque the shackle down too much, it won't have any movement whatsover, I may have torqued it down way too much with the old nuts that are on it now. Before I put on my new nuts, I would like to know about how tight they need to be. I'm also going to put these all metal nuts on my front spring eye bolts of my rear springs.
Is overtorquing them a big concern?

If anybody needs some 9/16 all metal locknuts, lemme know, I've got alot

 

[Citizen Rider]

Haynes calls for 90ft/lbs for the spring eye bolts.

 

[Slapperbar]

If you're going to torque lock nuts, find out what the running torque is and add it to the final.