[tharbert]

Mag cases commonly warp when dismantled making reassembly almost impossible. With no machining, as soon as you torque the case together, the crank will seize or the cam towers won't fit on the heads or the case will leak like a sieve...or all 3. Then, if you don't have a 7R, you're also looking at a few other mods to make the case right like piston squirters and the oil bypass mod. Then there's all the case savers you'll need for head studs and a few other important studs. So, yes, rebuilding a mag case costs quite a bit more.