/\ totally agree, i use a series one box on my zvh and didn't take long to get it to start making noises, as did the uprated series 2 box i had before.
i'm planning my zetec turbo now and block, rods and pistons are about a grand, not even talking about manifolds or head worsk and all elts and gaskets etc.
Luckily all other bits are there or there abouts to take the upgrade.