Re: GSXR600k1 vs. 1000k1 radiator hoses
They are interchangeable.
I've noticed that the last 5 numbers of the part# usually reference either 600, 750 or 1000. However the first numbers are sometimes the same across the board. I have a mix of 1000 and 600 parts on my bike. As long as you stay within the same generation, you shouldn't have any problems.
But some parts are specific, but mostly thats engine parts.
Hopes this helps..