I can't imagine that it would make a huge difference as long as the chain line is good. Ideally the spindle would be correct for the smaller ATF Campagnolo crank set. Last time I modified a spindle I found that the Camp. is .002" per side smaller than JIS. I just set it up on one of my precision grinders and ground it . After that I just looked for the correct spindle . If the spindle was right , then I think this would've lined up better. The down side to not having the right dimension is that there is not as much surface engaged inside the square taper.