I have a 2012 A/C 2.5 and just installed Tein street advanced coil overs which use stock front strut mounts (one of mine was busted so I bought a pair of KYB’s) and the torque specs in the Tein install manual says 43.4ft/lb but both have came loose. For stock struts the Nissan torque specs are around 73ft/lb so I’m just wondering if it being so much less for the coil overs is accurate or if anyone can tell me why I can’t seem to keep the top nuts in place. And no I didn’t re-use the existing nuts after I installed the coil overs.

That's an odd one... If you're not able to hold the top shaft in place while tightening, that can happen... but I want to make sure I'm following you here.

You are using KYB mounts on Tein coils, correct? Are we sure all other specs are accurate? For example., the thickness of the mount? If it bottoms out before the correct torque, you'll just spin it and it can loosen.

Tein coilovers with KYB mounts yes. And I use an open ended ratchet to tighten it so I can hold the piston rod in place with the tool that came with the coil overs, and then I use the torque wrench at the very end to lock it in place. Except it doesn’t seem to be staying that way. And then right after I get both tightened, I’m hearing a weird popping/creaking sound at low speeds when I turn my steering wheel that seems to go away once one of the nuts comes loose. So two problems I’m dealing with now and it’s super frustrating because I’ve spent all this money and can’t just enjoy driving my car.

Yeah, that popping/creaking is the top hat moving.

I'm guessing there's something missing in the assembly, which is leaving too much space above.

I'll get someone in here with a little more coilover expertise... hold please!

Are you talking about bolt sets 1, 2, or 3?
I've always just used the ol Impact gun on 1 and 3 once the vehicle is on the ground/under its own weight. Might have to use some threadlocker as well if it keeps coming loose.