To install these you will have to remove the old rubber from your old linkages, which is time consuming. There is no easy way but it helps to have a drill press so you can free up both hands. Use a drill bit to get out as much rubber from the end links as you can and then clean them out with a spinning wire brush. The new bushings will slip right in with the included lubricant. Use nylon lock nuts to keep free movement of the linkages. Do not over tighten.Short of modifying your suspension to a tri-link and panhard bar, hard core racers will tell you that the best thing to do is to replace your rear suspension links with new OEM rubber links, NOT urethane. The reason for this is the poorly designed 4-link suspension of the 1st Gen RX7s. The top links are way too short and will dramatically change the pinion angle when the suspension travel is too far up or down. And the off centered Watts link causes the rear end to shift side to side, bump steer. Hard bushings in the stock setup will cause the suspension to bind. That's why respected sources all say to stick with the OEM rubber for consistent handling. And if your links are original, the rubber has hardened. These issue are especially a problem in cars that are lowered a lot.I have RacingBeat springs, but they don't lower my car all that much. I can still go over dips without a issue. Yes, she corners flat.Along with the 4-link bushings, I installed the Watts Link bushings:After a few track days, my old original rubber links gave up the ghost. I could pick out pieces of rubber with my fingers. The old tired bushings caused a vague feeling in my rear handling, and the read end would suddenly shift over during a turn. On my last track session, I had several sudden spin outs. My RX7 used to gradually slide out the rear in a controlled manner. This change in behavior was alarming to me.I did some research on using urethane bushings on the rear of an 1st Gen RX7, and discussed this in some detail on the enthusiasts forums. Understanding the cautions presented above, I thought to give the urethane bushings a try. Honestly it's due to the cost. Buying OEM links with the rubber would cost several hundreds of dollars. A complete set of urethane can be sourced for under one hundred. The price on Amazon was as good as found anywhere.After having the urethane bushings installed for two weeks I can report that so far so good. I have not encountered any binding. Road noise is up and the ride is harsher, but that is to be expected. On the plus side there is more feed back from the suspension. I have been testing out the suspension on twisty, bumpy mountain roads. Let's say "spirited driving" but I pick my roads and conditions carefully. After driving on a real track, nothing I do on the street makes me excited anymore. Anyone wanting to street race should take it out to a real racing track to understand what the fear of God means.I have not had the chance to test the bushings on the track yet. But I think for the street they should be ok. Maybe a little harsh for a daily driver.Every vehicle and driver are different. Your results may very. Have fun, drive safe.For reference, here is my car.1985 GS RX7 12A stock portstripped interiorLSP rear with disc brakesRacingBeat springs and sway bars.48 DCOE WeberRacingBeat short primary exhaust.