there was an article in Grey Bike magazine .... they put a 600 engine into a 3en2. That used the 600 headers with the 400's link pipe and can, although the persuaded it to fit with a blowtourch and scaffolding bar

And if you want to read the article, click HERE

I knew that I had seen it somewhere!

http://www.fzrarchives.com/ipb/index.ph ... opic=41563

This should be a write up by an american, putting a YZF engine (probably an FZR, but you never know) into a 1WG 400 chassis. In this the author talks about changing the oil pan and pick up from the 400 onto the 600 to allow the 400 exhaust to fit.

Can't say if it will work at all, as I've not done the job!

Alex.

Just remember that America's models are a few years behind ours so a 1WG could mean a Genesis rather than an EXUP