Hi guys, searched around so if you know of a thread that addresses this by all means point me in the right direction.

I am converting a free-to-me oldschool road bike to fixed. BB shell is 73mm, Rear dropout spacing is 120mm and dropouts are horizonal so I'm in good shape there. I was gifted an old but still usable rear wheel with a 40mm deep V Velocity rim mated to a Suzue flip-flop hub. I then picked up a set of Fyxation Eastside cranks. The documentation on the cranks recommended a 68x107 BB. Being that my shell was 73 I got a 73x107 BB(this makes sense right?) With the cranks mounted and the rear wheel mounted the chainline was way off. I removed the cranks, moved the chainring to the opposite side of the spider and remounted. Still way out of alignment. Eyeballing would suggest 5mm+ out. Any thoughts on why things are so out of whack? based on measurements I figured this would be a little more straight forward (famous last words). Any insight greatly appreciated.

If people need pics or more measurements I have camera and calipers in hand. Nearest bike shop is over an hour away but I may need to make the trip