with stock cams they say not to go past 8k, there is no need though as stock cams peak at 7200, however with 16VE cams with stock valvetrain is good up to 8500 as the ramp angle on the 16VE cams is bigger so there is less stress being put on the springs, and even better with N1 cams as the ramp angle on them is bigger still. im going to be getting N1's and leaving the stock springs, but i will only be revving to 8k, the yanks think its going to be beneficial to rev it to 9k when there really is no point
mick, i have a unichip Q and the rev limit can be altered so when i get the N1's its going back in for it upping to 8k and a remap