http://mywebpages.comcast.net/datsun...d240zsway.html like i said the 19" is actually 17" sorry for the mispraint,,and the bar is 7/8

 

that is definitely not a Z swaybar, I have replaced mine, and it's not at all....maybe a truck?

 

exactly what year it goes to http://cgi.ebay.com/ebaymotors/ws/eB...tem=2422617497

 

I'm not 100% about this but it appears to be a rear sway bar for 240/260z

I just installed one on my uncles 240z and it looks to be similar.

The mounting location to the body is under the floor behind the seats just in front of the Diff cross member.
Your car will need the mounting brackets still intact on the floor. They may not be there if the floors have been replaced.

The 7/8" diameter is about right for the 240/260z. I think its too small for the 280z. If I remember correctly the 280z uses a 15/16" diameter bar for the rear.