No one makes a one piece gasket for the 340 pan, 5.2/5.9 only. It would be nice to have a one piece for the LA 318/340 though. If the regular gasket leaks, I will give my idea a try.
You can use the 5.9 gasket on an LA 360 but you have to modify the pan by welding in the little kick outs at the corners.
