KYB rear shock replacement issue: studs too short
 

84 FB GSL

Time to work on the rear suspension while the roads are still painted with salt.

The rear bounced like jell-o.
Got a pair of KYB's from Rock Auto.
Pulled the old ones out.

The rubber spacers, top and bottom, on the KYB's are significantly thicker than the squished originals. However the stud on top is 3/16" shorter. Combined together it was not possible to even start the first nut, let alone put on the top lock nut. (Image 1)
I tried the original top spacer, but had to compress it more than before to get the top lock nut on. (Image 2).
Image 3 shows the new bottom spacer and the difference in the stud lengths.
Image 4 has the original lower spacer in the same relative position as when on the original shock.
Image 5 made using the original lower and upper spacers.

Both the upper and lower spacers are more flexible than the ones that came with the new shocks.

Questions:

1. Does anyone see anything wrong with using the old spacers?

2. Which is better: softer or harder spacers? If harder (new) then should I reduce the thickness of the top and bottom new spacers?

Any other suggestions always welcome.

Thanks for your time.

As long as the old ones aren't falling apart (obvious cracks, etc.), I'd re-use them. When you cinch everything down, they're going to be about as hard as they're going to get - and honestly, it's just to locate the top of the shock; i.e., it doesn't have to bear any weight at all. Actually, to that point, if you wanted to use new rubber, just slice off an appropriate amount from the new ones and call it a day.

The point is to get them mounted and move onto the next thing that needs some work!

Thank you.
I have messed things up before from lack of experience and needed confirmation.

Don't reuse the old spacers. Dry rot, previously crunched... Just use the new ones.

You're gonna have to squish them to get them to fit in there. I wouldn't cut any off they are supposed to be squished out.

The act of turning the nut will squash the bushing.

I will use the new spacers, but due to the shorter stud I did trim 1/8" off the bottom one just so I could get the first nut started.