Reusable- yes. Should you- no. The gasket is like $6. Replace it. It's probably burned to a crisp. Don't reuse the turbo mount nuts either. Pull the manifold with turbo attached. It's much easier. Just make sure you have someone helping you, that shit will take out your back faster than anything. I'm sure a few other people here can attest to that. If you don't have any help, use something to pull it. That's a good 40 lbs'ish, and you need to pull it with your arms fully extended. Unless you can crawl up over the top of it, use help.