Well realistically with an engine that revs to 9Krpm I would start easy for a 100km or so and then gradually ease it to 7-8K rpm. By gradually I mean maybe go up 500-1000rpm every 50km of driving
With no WOT of course

Anyway, to give more info. The motor is a MIVEC. I want to up the displacement from 2 to 2.5L but I'd like to assemble the motor and then start on other mods for more power
Meaning, run it at 2.5L with the stock 2L cams, intake and extractors. The MIVEC makes peak power close to 8000rpm so with 2.5L I'd assume the peak power output rpm would drop considerably. Meaning also I couldn't rev it out too hard to run it in.
It'll be built with forgies and once all is done to it I would like to make peak power in a similar rpm range as the stock 2L (just so I have less issues with gearbox etc)

So, would it be ok to build it like this, or should I do everything at once?
cams, extractors and ITB is like close to $8K on the engine