I dont understand insurance, I'm with admiral and my n/a is like £400 a year, and when I phoned and checked what it'll be if I drop a turbo engine in they quoted me £350... No idea how that works? But if I were you I'd definitely insure it as a turbo, I know people who have been seriously caught out and done for no insurance because they had glanzas insured as n/as and even people who had 1.5L tsport yaris insured as a 1.0L with no mods haha. Its just not worth it. Plus as someone else said, if you have a bump it'll put up the cost of the rest of us trying to insure turbos :L