My heavy front axle is from another brand (JD ) machine, and the 1 inch steering knuckles are too short for the trailer hub mod.
So I am gonna try to modify them. They have a 3/8 tapped retainer hole drilled instead of using a castle nut like the 520. I'm gonna try and weld on some length using a 1 inch spacer drilled for 3/8 and make a different retainer. I'll grind out a deep "V" and weld it back up.
We'll see how it goes...