Mods needed when adding PCV system

[makomark]

I'm contemplating adding a real PCV system on my marine big blocks. The OEM system is only a pair of tubes running from the valve covers to the flame arrester; ie there's no "positive' venting going on.

Other than tapping the baseplate and adding a hose barb, I'm hoping nothing more is needed (carb-wise) than to reset the idle speed and mixture screws. Any thoughts from the "been there, done that" group?

tnx    mark

[Cliff Ruggles]

I can't see where adding it would be a negative anyplace.  Marine applications did not use a vacuum advance either, due to the "low" vacuum situations those engines typically see during use, as they are heavily loaded most of the time.  A PCV system should work fine, and it will help clean up the engine and extend oil change intervals, unless you are running around most of the time at full throttle!.....Cliff