just fitted an old dura-ace chainset with straight cranks. comes out at 130mm (2x 65 from downtube centre to crank face -easy way to meausure it) I guess that's pretty narrow by modern standards. The cranks I took of were those modern curvy ones.
Noticed better climbing - less pulling on the arms, smoother descents less bounce. Only problem I occasionally brush the downtube bottle with my knees.