Dude,
I've heard 50 micron being bandied about as the figure that the bores were out - that isnt going to kill a motor if its 50 micron bigger than it needs to be - only if its 50 mic smaller...Besides which 50 micron is that small that it would almost go through a fuel filter and be burnt in fuel.
The problem to me sounds like the car was tuned too keen too quickly, but hey what do I know about tuning a car - I'm not Japanese.
Dont knock CAS knocking - it works alright for us and SST, and I cant remember a car that we've tuned going bang at the drags.
Jash