It's so much easier (and cheaper) to buy a box of 72 spokes all the same length. I'm building some disc wheels with Stan's Crest rims using super comp spokes. Looks like I will need 260mm spokes for 3 sides and 262mm for the fourth side (the front right side). Will using spokes that are 1.8mm too short (according to spoke calculator & mfg specs) have any impact on the finished product?