Check the intake manifolds machined surfaces make sure they really are flat and true by using a steel straight edge to check for the surface being flat and true not warped, you will need to remove the studs for this, you can use a mill file to gently smooth the surface, don't go crazy with it, use the file in a gentle forward motion and don't let it tilt or rock when filing lift up the file for each stroke tap off the filings look at the files teeth each time as one little booger of aluminum still on a tooth will wipe out the work you have already done. You can see what is going on by looking at the marks your file is leaving. Poor boy machinist die the surface by using a dry marker and only smooth off the the surface to get the dry marker ink off, stop when it is off.
Another way around filing the surfaces is by using a slightly thicker manifold gasket and the dreaded silicone rtv and again don't slather it on use just a thin film on all gasket surfaces. assemble and check for leaks with the carb cleaner or starting fluid sprayed on the surfaces that you think are or were leaking if your intake/ air cleaner gets a whiff the spray it will speed up or die depending on how wild you get with the spray. I hope this will help.
Another way around filing the surfaces is by using a slightly thicker manifold gasket and the dreaded silicone rtv and again don't slather it on use just a thin film on all gasket surfaces. assemble and check for leaks with the carb cleaner or starting fluid sprayed on the surfaces that you think are or were leaking if your intake/ air cleaner gets a whiff the spray it will speed up or die depending on how wild you get with the spray. I hope this will help.
I've changed nothing else..........
