The lower intake gasket is leaking from the back of my friends 98 350 motor,I'm planning on helping him with this, I've done a few 3.1 & 3.4 GM intakes before, but I have not done one of these before. I have gotten some info about removal & istallation, about 15 pages worth, it looks pretty intimidating, I think we have all the tools to get it done. My question is this, is there anything else that I need to look for that may need to be replaced other than the thermostat, my friend replaced that last week. The gasket kit comes with upper & lower intake gaskets & valve cover gaskets, rtv sealant. Any help on this would great. thanks.