Fwiw, the exhaust manifold fasteners on these cars were usually held on by studs and nuts, and yes the studs went into the water passages in the exhaust manifolds. On MOST of these, with the exception being some of the performance manifolds that had a very unique deep nut from the factory, you can replace the stock nut with a BRASS nut , which will eliminate the problem of frozen fasteners and busted studs in the future. The same rule applies to the fasteners between the manifold and exhaust pipes, it may not be a big deal but someone in the future will thank you for making that change....maybe even you! Mikey 62 Crown Coupe