Well I have the same trouble with my car ..but the heads and the valve cover are the other way around.Eddy heads and old style cast alum valve covers. The angle of the new style heads and old style valve cover do not match.When you tighten the bolts down it pull them down wrong. I have try'ed everything and I come to realize that I need to buy a new style valve cover. so if you want to trade with some boot money let me know ! LOL I don't think my red ones would look good on your yellow car. they are power coated..but you could bast them and change the color..