I've got a gsr short block built for boost. It's got CP pistons with piston-wall clearance set at 0.004". CP recommends 0.0035" on these pistons so it's a bit looser as extra security on track days.

Now for various reasons mainly due to my local authorities, I'm going to run my motor NON-boosted next summer. For that reason I'm planning to use the stock PCV breather system for that stealth/stock look..

Will the increased clearances introduce so much blow-by that the stock PCV system will spew loads of oil into my intake? (causing detonation)

Or can I still safely use the stock PCV system as long as I'm not boosted?

 

i think you should be fine with the stock system in place until you boost. If nothing else, take off the intake every now and then and make sure there's not a ton of oil going into the manifold.