dansnoice

Doing a head gasket on my 2000 Impala with a 3.8. Got all the writing and fuel lines out of the way, fuel rail and upper intake/throttle body. I'm having an issue getting the crossover from front to rear exhaust manifolds off though. On the passenger's side bolt, on the rear side, there's a 9/16" square nut, recessed behind the lip of the flange that the bolt goes through. Tried a crowsfoot, tried a wrench, even went out and bought one of those gator grip sockets with the pins, that's supposed to fit anything. Can't get it, and there's no room to fit in a hack saw to cut it. How the hell do you get it off?? I need to get the exhaust manifolds off, to get to my heads. Special tool?