Don't bend it back, you may cause crack to spread. Id drill the edge of the crack to stop it's propagation and then torque intake back down and epoxy the crack. You could also put some wax paper under the china wall while your at it and backfill that crack with epoxy to create a new flat surface. The wax paper should allow you to peal it off after it sets up to give you a new flat sealing surface. Forget welding, epoxy is so much easier to use and it sets up like cement.