[bigj-dog]

3100s have both intake and head gasket issues. Usually only the head gasket problems if the intake problems have been neglected. If you're just going to do the intake gaskets (the lowers are the problem area) it's a one night project. Just make sure you buy the new fel-pro gaskets which are metal instead of the old hard plastic versions. I don't have a part number handy, but any knowledgeable parts guy would know what you're talking about.