So I have been trying to revamp my pcv side with an oil catch can setup. I have the stm 10 an fitting off the valve cover and 10 an lines to the catchcan, bt then have to neck down to a 5/16 line back to the intake manifold. While this setup work I have been looking for a way to maximize the flow. With that said I can't figure out how to remove the stock pcv fitting on the intake manifold so my question is is I drill and tap an new fitting into the body of the manifold ( more specifically the circle area right about the throttle cable bracket) will this work or is the oem location necessary as it sits above the runners, and may possible cause a venture effect pulling pressure out of the valve cover. Sorry if this is a basic question but I just want to make sure the planned drill location will have no effect on performance when compared to the stock location, and I can include pictures if I'm not being clear as to the location I am talking about.

 

You don't want to maximize flow on your PCV. If you do (particularly if the breather on your cam cover is going to a catch can that vents to atmo), you will be creating a large vacuum leak.

In my setup, i run a dual catch can. I didn't change the fitting on the intake manifold, and I used -8 lines (PCV side). With the non restrictive one way valve i used, even this sizing caused all sorts of headaches. Took me a little while to figure out that I had induced a vac leak.

 

As the above guy said. Either run VTA, or you need to keep the same size PCV fitting on the manifold. The car is setup for a "controlled" vacuum leak. By changing that fitting size, you increase and won't really be able to tune around it.

If you want to vent the motor more, get the -6 fitting for the other side of the valve cover, get the dip stick tube with -6 fitting welded on from STM, and run that to a catch can. STM also sells a fitting to vent the block from the balance shaft inspection hole, you can get that and run it to a catch can as well.