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Actually, the 2.5" stroke will give you closer to 7" of travel. The 2.0 should give you approx. 5.4" (Really basic rule of thumb is 2.7 x the stroke length to get total travel). As for the i2i length, 8.75" will mess with your frame geometry. A few people who have tried 8.5" have said they don't like it as much, although I can't see 1/4" being that noticeable either way. Nobody seems to complain when the i2i is slightly shorter though. 7.875" seems to be popular (that's the length of my Stratos and it works perfectly).