Hmmmm - working on my 6VD1 engined 3.2L VX today, I noticed what might be another difference.
(Or it could just be that you guys need to look at your own engines a bit better).

Standing at the front of the vehicle, looking at the engine, the PCV valve is in the right hand side rocker cover, and after the PCV valve the hose connects to the intake manifold just after the throttle body.
Now look to the left hand side rocker cover. At the same place as the PCV valve is on the right, another hose comes out of the rocker cover, but without a PCV valve. That hose connects to the intake air pipe, just in front of the throttle body.
Is that LHS hose the type of cross over you had in mind Tom??

Remember, my 6VD1 engine does not burn oil to the point of needing to be topped up between oil changes - it drops about 1/3 of a quart in 3000 miles.

Comments appreciated.

PK