So I've replaced the front inner lower control arm bushings and nothing else looked bad up front (already did the ball joints). Now I see the rear outer LCA bushings are gone and one of my indy's is saying they might as well change all the bushings back there, differential included. That's a lot of bushings and I'm not sure he's wrong, that if he's taking the knuckles out, maybe its a lot easier to do ALL the other ones. They don't look bad to me, only the LCA outers (in the knuckle).

Are these typical for failure and the rest not? Do they all fail around the same time?

Just trying to find out if I can know what to expect.

I had one of these fail at around 100k. Easy to check if they are bad. Just jack up the rear of the car and hold wheel at 5 past 7 or 10 past 8 position and try to shake the wheel, if the bushing is bad, you will feel play and hear a clunking sound. At first I thought I had a bad wheel bearing but I could only hear and feel the play at the above positions. No where else. A mechanics stethoscope pin pointed the problem area.
The bushing is not a rubber bushing but is a steel ball on a shaft inside of a steel casing that is packed with grease. Take off the grease seals when you get the old one out and you will understand better than my description
The bushings are cheap and easy to replace. Did it in my driveway in about an hour. All-thread and some sockets are all that are needed to extract and insert the new one. I don't see any need to replace other parts for the sake of it.

How does your car feel with the new front lower control arms done?. I think I have a bad front LCA bushing as the steering does not feel sharp and I get a steering wheel wobble when braking and turning hard at the same time. Rest of the time it is smooth except for some very slight steering wheel vibration form 45-50 mph.

Thanks for the info. The car feels great with the new front LCA bushings. Mine were gone. I developed the 45-50 mph wobble when they went, it was pretty obvious.

Just to make sure, you are talking about the rear outer LCA bushings that are in the rear knuckle not in the lower arm?

Yes, I was talking about the bushing that is inserted into the lower rear knuckle. It really is very easy to change and about $25 -30 for Lemforder brand. You used to be able to buy a special tool to press out the bushing but it appears to be discontinued. Just find suitable sized sockets or tubing once you get the bushing and some all-thread and a couple of nuts.
There is no need to compress or remove springs etc. Simply put car on jack stands remove the wheel and loosen the nut holding the lower control arm to the knuckle, put a jack under the control arm and gently raise until the bolt can be removed easily. The shock will stop the arm dropping too low and releasing the spring. Then go at it with the sockets and press the old one out and press the new one in.
Glad to hear the front LCA bushing helped you out. Did they wear gradually or all of a sudden you got a wobble ? I have the new front LCA bushings and just ordered the bushing removal tool and spring compressor and will change them out in the next few weeks.