PCV tube/elbow was one of my thoughts but it wasn't rotted as I've seen on other vehicles, I also plugged off the brake booster, evap, and vacuum ports to no change. However, now I feel quite stupid(Ahh yes human error came back to bite me in the ass of course) Upon reinstalling the throttle body to intake the first time, part of the o-ring(about 2" worth) gasket popped out and cut off when torqued down, falling into the intake resulting in quite the vacuum leak. Replaced the seal again and fuel trims and sensors are behaving the way they should be now.
Buddy_M's post in 03 V10.. Idle and fuel trim questions was marked as the answer