Can anyone tell by the pictures how the bushings look?

 

no expert but just did strut bushings with polyurethane (not trailing arms)..

trailing arms look ok visually to me. the bushings in strut rods are ready to be replaced but not horrible... IMO..
driveabilty issues? wondering rear end? I would like to replace my trailing arms with new rubber but without me seeing damage visually i'm waiting..
below is my strut replacement... NOTE so far I really LIKE the USA made poly bushings.. no squeak seems very 'snug'
you will also see great advice from others in my learning thread
https://www.corvetteforum.com/forums...od-advice.html

 

This can quickly escalate into a complete rear-end rebuild.

The trailing arm bushings do look intact. Someone has clearly been in there before. The twisted wires that are holding your (non-stainless) shims in place are not stock. At the very least, if your alignment shop is interested in taking another crack at this, pick up some stainless shims and the proper long cotter pins to hold them. With the old shims out (they look loose), you can better assess the bushings. My bushings looked okay, until I cut the trailing arms out of the car.

https://www.zip-corvette.com/63-82-t...stainless.html
https://www.zip-corvette.com/64-82-t...-shim-pin.html

The strut rod bushings may be marginal. These photos were taken on jackstands, right? The strut rods are adjusted to the limit of their camber range. Is it sufficient when the wheels are loaded?

Finally, while the car is in the air, consider changing the rear differential fluid. It looks like one of your seals has a leak, and is flinging fluid onto your car. New fluid won't fix the leak, but it will let you check if the old fluid is low, or has a lot of metal in it.

 

It doesn't look too bad under there and appears original. The TA bushings don't show dry rod but they do wear where the inner sleeve is. They flex at that point and over time play can develop. The diff is leaking oil. rods don't look bent, shafts look in good shape.

As Bike said this can easily turn into a full rebuild.

Assuming the IRS is original then you have some concerns to deal with.

78's had differential issues, specifically the axle faces were soft, clutches weak, ring gear bolts not good. All led to big problems. I would look real close at those axles to see if they have crashed into the housing yet, that will cause a leak and could wreck the housing if left unchecked. The clutches should break away at 40+ Ft/lb with one wheel locked but I wouldn't bother trying to rig up that test. The ring gear bolts backed out and the only way to know is to pull the cover, which means pulling the diff out of the car, which means do you check it or address the known issues.

The grease used back in the 70's was that brown pasty stuff that dried out. The outer axle bearings may or may not be dried out, no way to tell other then taking them apart and then you are into rebuilding the arms. Forget about rear bearing grease tools they don't work, well they will pump grease into the inner bearing somewhat but won't get to the outer and if you did pump it up to displace the air in the support to reach the outer bearing it will blow out the outer seal and you will lose the grease and for sure have to rebuild them.

If you are just building a street car, not a road racer, the stock rods are fine with new rubber bushings. Finding a competent alignment shop is more of a challenge.

U-joints are a direct repair, using solid spicers would be my choice.

I have threads covering all this work with a lot of pictures. Someone brought back one of the diff threads the other day, check that out there might be a reference to the diff issues mentioned, I don't really recall after 20 years of posting this stuff all over the world wide web.

 

Totally agree with all the above. Trouble aligning the rear end isn't solved by adjustable strut rods. There nice. But worn axle faces are very common with these cars. Replaced mine years ago with the better hardened one's. Lots of things to look at on a car this old.