Finding inner tie rods can be a real bear for the Z cars. These inner tie rods are thankfully now available. 

Direct fit to the 240Z, 260Z and 280Z. 

These inner tie rods are only available in right hand threads, so please choose your outer tie rods accordingly or check to make sure your existing outer tie rods are right hand thread. 

Originally the inner tie rods on the  Z used a right hand thread on one side, and a left hand thread on the other side. Some time in the 80's Nissan discontinued the left handed thread inner tie rod, so any replacements were made by changing the inner and outer tie rod to right hand thread.