I didn't have that many problems getting one off. I found the best condition one with the cleanest bolts/nuts. Only required a quick squirt of WD40 oil. You need to find one in good condition.

I had troubles fitting one on my CA18 1200, it hit on the CA sump. Apparently it might fit in upside down? If you get the chance, try and fit the swaybar in upside down and see if it fits. I don't think it will, because the bar is not flat across the section that bolts to the datsun subframe.

Cheers,
Chris.