I replaced the rear trailing arm bushings last year. My experience in my '86 is the trailing arm bushings were in very good condition - very little distortion or aging of the rubber, so did not notice an improvement. However, they are new and I will never touch then again.

Mapp gas will remove the inner sleeve and the rubber in about 10 seconds, then you have to remove the outer sleeve. I got a hacksaw and carefully made a cut in the outer sleeve, ensuring I did NOT cut into the aluminum arm. Once the outer sleeve could be bent inwards, heat and a hammer removed them. It took me close to an hour to remove each bushing IIRC. I'm not sure I could have avoided the hacksaw with lots of heat.

You need to make certain both bushings are fully seated or they won't fit back in the mounting point.

Thanks Nick. I am looking at the Tarett adjustable as they are around $260 for all 4 and are adjustable which will help with corner balancing.
I am not planning on increasing the size of the sway bars so I am not too concerned about reinforcing the shock towers, although I will be checking the "health of the metal and presence of rust.

Bumping this fairly ancient thread as I'm about to do much of this work and this seems one of the better threads I've found discussing it...

'85 930 Turbo I recently acquired, stock suspension, drives decently but I know it's way off what it can and will be.

First I'll do a thorough inspection, then I guess I'll have to decide what bushings or monoballs to use. Strictly 'fun' mountain and canyon drives. Little or no track work, I have other cars for that.

Any thoughts or advice welcome, as well as any pointers to other threads that might have great info.

For a street car, I like the OE rubber bushings. On the recommendation of several people, I put the Rebel Racing solid bushings in my 1973 street car. I can't detect much difference in road noise on smooth roads, but on crappy roads they do transmit more NVH (noise, vibration, harshness). On the advice of William Knight (Knightrace), I have stayed with the rubber bushings in the rear arms, because the monoballs will increase NVH more.

If you usually go out for short drives, or your roads are mostly smooth, maybe solid or semi-sold bushings will work for you, but I drive distances with my car, so I want to minimize NVH.