i think you can do it with 240z and early 260z legs as the tubes are smaller but then they are bigger on the later 260z and the 2" will not fit ,but if you are thinking of doing that MrG240Z was wanting to swap his Leda's for standard 240z legs which you could consider.
the leda systam is quite good as they do not have a shocker insert as such and it is called a wet system as the leg tube is the shocker with a damping rod built into it ,it is a expensive system to have converted to (about £2000)but you have it it is quite good,i have just had mine refurbished by Leda with new rods ,checked and painted and setup for road use for £326 which i think was excellent value .i will post some pictures soon .