iff the leverage ratio stays the same the shock spring rate and damping can stay the same.

concerning the linkage the stroke should be measured and compare it to the swingarm. 

 hence if you can find a spot on the swingarm where both the stroke and leverage ratio dont change you are good.
if either changes the spring and damping will have to be tuned.
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i can see u wanting a shorter swinger. my lt250 lays really flat and light on the rear end.  the lt500 seemed better to me - i figured it had a taller CG
and more weight.

i like both but i like the 250 low cg and lightness better.  i throw it around with one hand. the 500 slays my back. i only weigh 160.