Okay so I have an explorer 5.0 with the GT40P heads. My plan was to pop the heads off and swap them over to a fox body 5.0. I got the gt40 heads off and noticed that they're valve reliefs on the pistons. Was this common on the explorer engines? I remember reading somewhere that the explorer/mountaineer 5.0s didn't have them. I also read that the pistons aren't good for boosted applications. I'm wondering now because this explorer 5.0 only has about 60k miles on it. If it turns out it has the forged pistons, I'd want to toss the heads back on and run it.