hey Bill, yes, i have a lot of time for the 400, i have a spare 400 lump complete, which, when #1's lump was on the bench i bunged in the chassis so's i had 'wheels' , the 400 revs up so well, is smoother, although not quite the same pick up, it's not far off the same top speed.
bearing in mind i used the 600's CDi and carbs, and my Competition Fabrications s/s sporty exhaust system.
obviously you know that the twinshock engines (600 & 400) won't slot into the mono chassis , bolt holes ok, but chain alignment is crap.
sent the stuff requiring painting away, now prepping wheels , swingarm, fork tubes, sprocket carrier for powder coating.
am planning on getting Competition Fabrications to knock me up a few chain guards like i have on #1, might take a punt and see if anyone else is interested in a nice s/s guard, post a pic on here and ask the question.
pip pip