Got a 97 f150 4.6 with 176k on it. Only had it about 2 weeks now. Runs great. Just some minor things need fixing? like new cv axles upper and lower ball joints on both sides and a rear shock bracket. Nothing I can't do myself. But I noticed it's leaking a little oil on the top part of the engine in the back on the passenger side. I've read that the head gaskets are known to leak oil. Would it be foolish of me to think it is the valve cover gasket?