friend and i are doing a conversion project.
new handle bars, tape, wheels, the works, but i just wanted to make sure im not forgetting any important left out details...
sugino 75 cranks and bottom bracket with english threading.
im not going to run into any problems with this right?

besides getting the chainline perfect on 126mm spacing, i think we have a fightin' chance.

oh yeah. 126mm <i>rear</i> spacing.

Why would you put a $250 track crank and BB set on a 70's department store frame? Not that there's anything wrong with it, as long you can find a 144 chainring that will clear the chainstays.

Agreed, get a more reasonable crank.

This is friend number two (and we're having a good time)
And because we're getting the crank set and BB together for about $100
What would you put on it?

I would say either any 130 road cranks, or maybe the Sugino RD2s. If the frame is going to be able to deal with a 46T chainring at 42mm and you're getting the cranks for a song, no problem - but you might need something a little smaller with a conversion. Your bottom bracket is most likely going to be flexing before the 75s do, regardless.

yeah, hang onto those 75s because you're likely to have clearance issues. the XD is actually a pretty clean looking crank and it's 130bcd if memory serves. if it matters to you, those forks feel kind of sloppy/flexy; i've come across them several times in building older conversions for friends. see if you can pick up an alloy tange or SR in the depths of your LBS or coop— it shouldn't cost more than $40 and will vastly improve the handling.

The XD is 110, takes a 107 BB. Very nice crank. The RD2 is a no-go now that they messed up the chainline, you need a 107 BB, the chainring in the inner position, and probably a spacer. The 75's may actually fit, depends on the ring.

hmm, XD is 110. that might limit the availability of track rings (which ideally are a bit stiffer and rounder, OP). sinz and rocket both make 1/8" rings in 110bcd, but no sugino zen or salsa, i don't think.

i doubt these guys really care about having a stiffer, rounder track ring.