Yep both those sleeves vent the same area; the sump. I've got two hoses on mine (it's NA but) running down into a chassis rail (shhh). There's been a lot on ausrotary about crankcase ventilation and when they're blocked (especially on the later stuff) they blow smoke (especially on deceleration). Vacuum is probly best, venting to atmo is ok, but I'd say blocked is not that good. In Au from what I can gather (not sure about here) it is illegal to vent to atmosphere.