Hi all.

I am in the process of swapping my plenum on my 3.9 hotwire for a 4.0 plenum from i believe a late 90's P38.

The reason is i have 2 brand new P38 plenums sitting in my garage and my 3.9 one was fooked.

The issue is because the 4.0 versions are not hotwire they dont have the stepper motor on the rear. I have fitted this easily but the connection to the throttle body (pipe in the rear) is also missing.

Can i hook it into the pipe at the front (which is for the breather/flame trap originally) and have the breather loose?

I cant see why not but i want to pick the brains of you guys first in case its a big no no.

I believe that on the 3.9 both the stepper and breather pipes share a common airspace within the plenum.

cheers for any advice.

personally i cant see a problem with having the breather open to air.

but then again you could try just T into the breather with your outlet from the stepper valve, then youll still have positive rocker evacuation.

excellent idea!