I can't understand whay anyone would "toss" the cylinder head studs that Ford originally installed, and replace them with bolts. Using studs allows getting a more even, accurate torque. Sealant can be applied to the threads before the stud is screwed into the block, and allowed to "cure" before the head is installed, preventing any chance of water leaks up past the fastener head. And there is less chance of ever damaging the threads in the block when the proper stud is installed and threaded in to "grab" the threads in the block to the intended depth. Here's an excerpt from the ARP website (a premier manufacturer of quality high-performance engine fasteners). They also advocate the preferred use of studs over bolts. (Not that the old low compression "N"'s can be considered "high performance, but with all the trouble some guys have with head gaskets and leaks up by the fastener heads, some of these projects need all the help they can get!) From "ARP BOLTS.COM": "For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode—never crank it in tightly using a jammed nut. If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run."
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