I've got the intake pulled right now as I change my head gaskets, and I notice that there's a riveted plate underneath. Is there anything underneath the riveted plate, like a core plug or something? If there is, now would be the time to check it, but if there isn't, I won't mess with those rivets. Strange question, I know, but I hope someone has messed with one before.
It is a heat shield. While I haven't pulled the heat shield on a 300 SBB intake, I have pulled it on others. Nothing there to be seen, sometimes the date the intake was cast is located there, which is why I pulled one off. Maybe someone else has more information on your specific intake.
