I read on Sheldon Brown that JIS crank on ISO BB brings the crank arm 4.5mm further in /closer to the frame.
This concurs roughly with my experience with using a shimano JIS crank on a Primato ISO BB and had similar results using a stronglight JIS crank on a Campagnolo veloce ISO BB... although I didn't measure down to the 0.5mm
This concurs roughly with my experience with using a shimano JIS crank on a Primato ISO BB and had similar results using a stronglight JIS crank on a Campagnolo veloce ISO BB... although I didn't measure down to the 0.5mm