This is kind of linked to the 33bhp issue in the other thread.

OK, so I want to put a 600 motor in my 400 but then I've got to disclose that to my insurers. Right, fair enough but do they jack up the premiums so much that I may as well just get a R6 or is it a reasonable increase as it's not that big a jump in power?

When I looked into it I was told I needed 3 years full insurance and then the quote came in at around 180 ... this was with Footman James.