If the slave cylinder has a chance to open up (extend the rod) then it needs to be bled. Also with new clutch installs its a good idea to bleed them anyways, because usually the engagement point moves. The reason it moves is due to the fact that now everything is back to 'spec' (correct thickness clutch disc, correct step height, new TO bearing). The clutch hydraulics actually adjust overtime to keep the system moving smoothly.
You might also have to adjust the throw/engagment point on the peddle due to the longer rod.
good luck

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