They are indeed 2.5" long, and the included nuts do indeed screw onto the fine threaded end of the stud. Those are the good things. The bad involve the coarse end of the studs, and those fine threaded nuts. The coarse stud ends won't accept any 5/16" nuts, so I certainly don't want to force them into a manifold. I could clean them up with a die, but should I? The fine threaded nuts accept a 7/16" wrench or socket, not a 1/2" one. I suppose these studs can be used, but I would just rather not.