I'm tearing down an '81 200, and the exhaust manifold bolts are rusted on pretty well. I've been soaking with PB Blaster for a couple of days and no luck. Next will come the torch. But my question is this: what size are these bolts? My 1/2" socket is too small, 9/16" is so loose I'm afraid it'd strip the heads. I can squeeze a 14mm open end wrench on it, but not a 14mm box end. Could it actually be 17/32" bolt, or is it a 1/2" that has swollen with the rust?