So I just bought a Bianchi Pista off my neighbor and got a great deal because he never rides it. I put a BMX freewheel on it and noticed that it threw the chainline off by about 10mm.

I was considering replacing the crankset anyway and noticed that the Sugino RD gives you a 45mm chainline with 103mm spindle length BB.

Currently the bike has a 103mm BB with a crank that gives it a 42mm chainline. So the Sugino crankset alone would get me 2mm closer to the proper chainline.

I noticed that the Sugino RD can also take a 107mm BB. So if i were to get a 107mm BB and the Sugino RD does this mean that It would move the chainring out a total of 7mm? Thereby giving me a much closer chainline, or is this completely convoluted logic?

I've searched the forum quite a bit and haven't been able to find an answer, or if I have it has gone right over my head because I'm pretty new to bike mechanics in general. Any answer would be appreciated, thanks.