2002 Alero CV Axle Replacement

I successfully changed out the driver side CV axle with a re-manufactured axle, but I have a question. As I understand from these forums and searching on the internet, there are 2 different axle nut designs. The original black PAC-style nut torqued to 285 ft-lbs (with I believe some sort of integrated system to keep it from loosening), and the second design which is torqued to 173 ft-lbs. The nut that came with the axle was not the PAC style which I took off the old axle, so I assume it is the version meant to be torqued to 173 ft-lbs. My question is, how is this new nut retained? There are no tabs to bend down to lock the nut. Is the torque alone enough to keep it from loosening up? Should I replace with the original PAC style nut or find a new PAC nut? Thanks in advance for any help.

The new nut is a lock nut, should be tapered in a little on the outer edge(the back of the nut) install it and torque it to specs and you'll be fine.