you have any airflow diverters inside there?

dont block off the two crankcase vent holes that used to be part of the PCV system...i see you already have one threaded....you can tap into these and run simple 3/8ths hardline for each bank to have its own vent to a catch can/breather tank.

its craploads better than the VC breather or VC located vent hoses as the factory LIM will condensate and get the oil to fall out of suspension and drain back into the motor as opposed to sending it to the breather tank.
this is the FWD NA LIM but you get the idea