okay so i'm replacing the crankset on my beater.

currently running fsa cranks on a 107mm shimano un55 bb (i think fsa recommends 110 or something). i wouldnt be able to use any shorter of a spindle with these. i got the chainring on the outside, formula hub, origin8 cog, and what seems like a pretty straight/quiet chainline.

i might buy some vuelta pista cranks i found for cheap, and i was wondering. if i use them with my 107mm bb, would i have to put the ring on the inside for 42ish chainline? or should i just get a 103.

also this might be ******** but for example if i used my fsa's on a 103mm bb, the cranks would slide on so far as to touch the bb and wouldnt be able to get tightened all the way... i dont want that to happen with the vueltas and waste $25 on a bb. and i also dont want to run the chainring on the inside.

do ya think a 103 would be long enough to stick vuelta cranks on?