I have just put together my 1971 Challenger with a mildly built 340. I replaced the old radiator cap with a new 16lb cap. I am having trouble getting the neck to seal to the intake manifold. I used a quality sealer and gasket but when the system pressurizes, it leaks through the gasket and up the bolts that hold the neck on. Should I go to a lower pound cap? The manual calls for a 16lb cap. Thanks.
