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Ok, going over the bill of materials for single precision, it requires: 1 GT2-20 pulley (isn't this the one that is on the stock y-axis?) and 1 608 bearing (aren't the 624 bearings that come with the 2014 1405 the same size, or at least usable?) I have 406mm rods/new belts ready to go in and hardware, I don't think I need anything else?