Poly Lower Control Arm Bushings VS Rubber

They WON'T work their way out, and CAN'T. I used them on my 72 and they were fine and didn't squeak (much).

Something to keep in mind when installing is that you typically must re-use the inner and outer shells of the old rubber bushing. Essentially you are just replacing the rubber part. This has the advantage or disadvantage of not requiring the old "can" to be removed from the LCA. They require a bit of work to remove, but then again getting all the old rubber out can be a messy job. Same with the inner sleeve. It's usually stuck on the pivot shaft, but you have to clean it off. I think somebody makes/made pivot shafts with a larger OD which fit the bushing directly.

Another potential issue is the "head" of the poly bushing is bigger and may position the LCA slightly more rearward. This will tend to reduce caster. I don't recall this being an issue, but the last set I installed was 18 years ago. The length of the bushing could easily be adjusted with a belt sander if need be.

Are the poly bushes better than a quality OEM type? Maybe, but probably not much. If your old bushes are in bad shape replacing them with anything will make a huge difference. Replacing a good OEM bushing with poly probably won't make a noticeable difference. For a road racer Nylatron or even solid bronze bushings would be best, but they would be noisy on the street.