The axle and the hub are both splines with a tapered spline. The taper is what wears down when run loose and causes the hub to push too far back to be able to tighten it up on the spline.
No you will probably not be able to get that much torque on the two piece. (Swaggert) nut. It is something like grade 8 at the most and the original is forged steel and hardness you wouldn't beieve. Just tighten the inside nut till it starts to want to slip and then tighten the outer nut so it squeezes down on the inside nut and tighten it some more alternating till you get it tight as you can without it slipping on the threads. I have used a lot of these nuts and they work.
You need to retighten it several times after working the tractor for an hour or so because it will work the hub up on the axle spline and get loose again till it get tight enough to stay put.