Advice for CCD settings?

[Penguin]

I've recently acquired a used QHY163C camera to replace my 450D and I'm wondering how that should change the way I do things. Particularly, how do I choose the gain and exposure settings? It's looking through a Skywatcher Explorer 200P with a coma corrector and is on an unguided EQ6-Pro if that makes any difference. Can anyone give examples of suitable starting points? With the 450D I set the ISO to 800 and tended to do 1 minute exposures. I think I now have the alignment sorted so could probably go to 2-minutes and I intend to get into guiding hopefully during this winter.