Tech is right. I have a 77 LTD 302 and am having a few problems that I cannot figure out. One is that my drivers side valve cover is FILLING up with white foamy milky moisture. The PCV valve goes into it and is doing it. I have vacuume comming out and tried changing pcvs but don't work. I have a LITTLE bit of water in my oil on the dipstick but not much and am not really loosing water... Not much anyways because I can't see the level dropping. I changed my manifold and all and after I did this I am having all these problems. Tech, you just gave me an idea and you may be right, there is definetely something wrong with my manifold or something.... I have been working on it like crazy and am sick and tired of messing with it and tearing it all down and buying 5 pairs of Fel Pro gaskets.
Take Tech's advice very seriously or else you will end up with something that is a total pain in the ass like I am dealing with. I still cannot figure out my problem.