I run the 440 Source valley plate, Stealth heads and a Torker II on mine. The valley plate leaked badly when I first got it running. Turned out that the bottom of the intake was contacting the plate and breaking the seal where it seals to the heads. I'm pretty sure the intake would have cleared the factory style valley pan. It was an easy fix, the bottom of the intake right under the ports required some grinding to stop the interference.