There is a non-serviceable metered orifice fitting on the block with a hose running to the induction hose before the throttle body. Much discussion on this hose and fitting as that is the source of the oil puddle in the intake tube. This fitting can get clogged and the Camaro owners have come up with a mod (drilling larger holes in the fitting) to improve things. There is also an insulated tube now available to keep the oil vapors from condensing so fast and coating the throttle plate which causes poor running during cold weather.