I am looking to buy some new front shocks for my 81 model RX-7. Have seen where I can buy replacement shocks that are the inserts. My car probably never has had new ones. How can I tell if it will take the replacement cartriges which are for rebuildable shocks?

 

Are you asking where to buy replacement shock cartridges? Mazdatrix.com sells a variety for your car.

There are plenty of old threads on replacing front shock absorbers. use the search function.