I'm about to put some "17s on my corsa and wondering if I can fit with no problem a 320mm brake disc. And would it be necessary to change the caliper as well?

brought these off ebay they nearly fitted! just centre section wouldnt fit all way on... so up for sale never been used £20 for collection or postage on top of the £20 http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=220163864747 Thanks Joel