I personally never had much luck with the rubber end seals, although you are right the ones with the little alignment pins seem to stay a little better. Someone had mentioned Permatex "the right stuff" earlier, I've had a lot of luck tossing the rubber seals (as GM did years ago) and using a bead of that. I normally just put a real thin wiping of RTV around the water ports, helps hold them too while you are positioning the intake. my 2cents
