Suspension bushes / tubes.

[Enoch]

Hi folks, I am a bit unsure about the suspension bushes and tubes - the crush tubes are 44mm long, the bush tubes with bushes installed are 44mm long and the suspension brackets have a 44mm spacing. This means that when I do up my bolts some of the bushes are effectively clamped by the suspension brackets and make an awful noise when the wishbones move up and down. Am I right in saying that the crush tube should be kind of clamped by the suspension bracket and the bush then is allowed to rotate around the crush tube? Or do I just not tighten them up so much and the crush tube rotates around the bolt? I hope that makes sense. It just seems a bit strange that the crush tubes are not 1-2mm longer than the combined length of the tubes / bushes.
Thanks in advance,
Enoch.