I assume I got a bad pair, but apparently it's happened to other people. On the advice of a more knowledgable individual, I bought some OEM evo/twin can intake seals at the local H-D dealer. My friend told me I would find the S&S were substantially smaller and indeed they are shorter in height by a couple millimeters. Upon installing the OEM seals I had tactile feeling of rubber compression many turns before bottoming out the bolt and recalled there was zero indication of compression of the S&S seals that immediately failed. I normally don't write bad reviews, but I sure wish there was one here when I bought saying to go with OEM if you have a motor with stock H-D heads. I would have been riding all this past week!