Michael-Those are big torque numbers!
What has been your experience with axle strength? I think you will find that your ae stubs will break (inside the diff) before your wheel flanges will break. From what I have heard, the aluminum 5-lug front hubs push the front wheel offset out toward the fender. You might be ok with skinny front tires. If running wide tires, I would look into having stock 280z hubs re-drilled to try to maintain stock offsets. In the rear, with that kinda torque, you might as well consider a solid axle like an 8.8 or 9".