For some reason, Amsoil oil filters typically do have a bypass valve in the filter for the GM apps that do not require them. I always wondered if this was a sort of double safety feature in case of the unlikely event that the one in the engine siezes in the closed position and does not allow bypass, leaving the filter unprotected from excessive pressure in certain situations.
BTW, the Amsoil number for your app is EaO59, and is probably the only one available that has a bypass valve built into it.