Once the air is metered by the MAF, it must stay in the system.
On a blow thru all the venting is way upstream of the maf so it does not matter where it goes.
On your draw thru, you need to dump it back like in the last picture.
Is a T70 a little on the large side for a 3.8?
Erich

 

the problem isnt where the air that is purge goes, its where the air is coming from when the bov is not closed. if its drawing in air and the MAF cant meter it the car will run like ----.

Air shouldn't be coming in from the bov!