If it is a solid tubing looking thingie about 3/8=7/16 long its a solid spacer

If it is a piece of thinner tube with a wrinkle in the middle its a crush sleeve

Pics of your parts would help

A solid spacer is easier to reinstall ---if a crush sleeve it will take many ft lb of torque to crush it and you will need a new one---Ford still uses the same 1957 crush sleeve to day in their 1 ton trucks----