... something to to keep in mind, from memory the Naish bar has a high Y point and the Cab has a low Y point (Y point is where the height at which the front lines split). This will put different pressures on the kite and basically not work too well, as in if you put high Y on Cab the kite will be pinched in (icecream cone effect). Tried many experiments over the years and found, put the original intended bar on the kite makes it work best.
I recommend you mimic the original bar for best results.
cheers,
Robbie