Magnum exhaust manifold studs.

Are you trying to use the Magnum manifolds on a Magnum or an LA? If it's on a Magnum there's no need for studs, all the exhaust bolt holes are dry. They just used bolts from the factory. If you're putting them on an LA, just use bolts and sealer on the outer two bolt holes, it'll seal just fine. The studs were just used to maintain the seal on the outer two wet holes in case you need to remove the manifolds- with bolts, you just have to remember to drain down the coolant a bit before you remove the manifolds.