Do NOT change the gaskets. I am using Felpro gaskets on my Edelbrock Performer series intake manifold and they are the best. I at first used Mr Gasket ones and they leaked like crazy (part of it was my fault but not all of it). But anyways what is your problem? You said something about stalling when putting it in gear and that's all I know. Reason I ask is that if your question is what I am thinking it is then we both have the same problem here on a different one of my trucks (the one with stock intake manifold and gaskets so no worries on that one heh).