2000 Trooper Exhaust Manifold Studs

Can anyone tell me if the three studs that hold the front exhaust pipe to the front exhaust manifold are knock-out studs? I think I cross-threaded one of them and I'd like to either chase the threads or replace them.

Thanks,

Larry

Larry, in the event you didn't get'em out by now.. I think most years used knock out style studs on the collector end of the exhaust manifolds. Those can be a PITA after some years of service.
G/luck
Joel