how much shorter are 300ex shocks than 400ex

[budred400ex]

i was wondering how much shorter 300ex shocks are than 400ex and if i can use 300ex shocks on my 400ex for tt racing witha lowering kit on it or would it be 2 low then

[RRP]

I do beleive they are about 3" shorter

[budred400ex]

so can i put them on my 400ex for tt and flat track racing and also with them on can i buy a lowering kit and put that on