I got the leak to stop... Stupid thing to fix it... The breather hose that goes to the air cleaner was pinched off and i put an elbow in there and got it so its open and would ya know it no more leak! simple fix

The valve covers are the mr gasket chrome ones. Nothing special. I have gonna try double gasket tomorrow.

I took the valve cover off yesterday put a nice even bead of silicone all the way around the valve cover and around the bolt holes and let it sit over night before putting heat to it and come to find out today after driving it a few miles it still leaks!! I dont get it. Should i try a rubber...

It seems like when im going through mud or putting any load on my pickup that I cant seem to pickup any rpm.. Could this be a timing issue?I just recently rebuild this motor and it did this before the rebuild as well. Any help would be great!

Alright thanks guys.

Are you talking on the head or vc? Has anyone else ever had this problem?

Its leaking on the bottom side seems like the whole length of the head. Cork gasket should I try rubber? The vc is pretty new.. should I just use silicone no gasket?

I have a 400m that i just cant get one valve cover to seal up. Its the driver side valve cover and it doesnt seal. The other side seals perfectly fine.. The valve covers are after market mr. gasket chrome ones. Could this be a warped head?? please help!! iv tried everthing!

Hey, I have a 79 400m with aftermarket chrome valve covers and on the driver side valve cover always leaks no matter what i do.. The passenger side doesnt leak a drop.Could this be a warped head? I just rebuilt the engine and it happend before the rebuild as well on the same side.. i dont get...