I'd pull the engine and change the pan gasket and get a better and easier jog. While you got it out, pull the exhaust manifold. I'm sure if you're not confidence you can get the broken stud out yourself that a machine shop would remove it for less than $25.00 and you'd have the right manifold on the engine going back together. If you don't have a 3/8 thread chaser to clean up the other studs, you might have them chase them for you. On the other side, try some liq. wrench and move them a little each way until you've loosened (
)them up. G.L.