Valve Cover Leaks

[Sulley]

One thing I hate is anything that leaks under a car. Once I got my Manta Mirage I resealed the trans-axle, oil pan, and valve covers as they were all leaking. This is pretty 101 stuff but I continued to have an issue with my valve cover gaskets on the Chevy 350. So here is what I did to stop the leaking valve covers on my Manta Mirage 350. It maybe helpful to other novice DIY'ers battling with this issue.

When I last replaced these I spent extra money to get 'high performance' valve cover gaskets thinking it would be worth the extra $. Unfortunately in short order after removing the valve cover the gaskets were already hardened. So the process I went through was as follows:

1) I purchased new cork gaskets but thicker ones hoping that if there were any irregular areas on the valve covers that this would help seal them better.
2) Remove and clean old gasket material and thoroughly dry.
3) I checked the valve covers flanges for any uneven or irregular areas from over torquing of the bolts.
4) I used the extra valve cover hold down flanges. These are very thick and my theory is that they would help to evenly distribute the pressure across the valve cover. I only used on the lower 2 bolts of each valve cover.
5) I needed to re-bend these as they had been over torqued in the past likely by me and the pressure was not evenly distributed as needed. With the adjustments that is corrected as you can see in the image.
6) I used a spray adhesive and sprayed ONLY the valve cover and one side of the gasket and positioned it exactly where it needed to be so I was ensured a correct fit when I installed the valve cover.
7) No silicone used!
8) I used new lock washers as mine were flattened out. My engine has a big cam and I needed a lock washer to prevent potentially the bolts backing out.
9) When installing the valve cover, one side of the gasket has 2 holes and the other has 4. Position the side with 4 up as to reduce potential leaks.
10) I slowly hand tightened with a socket and extension and just my hand each bolt until they started to get firm doing so in a rotating pattern around the valve cover.
11) Once they started to get firm I only 1/4 turned each one in the continuing random sequence until they stopped. The key is not to over tighten but get them tight enough.
12) I ran engine and after it was warm I again rechecked the bolts and re-secured.

I'll drive today but so far so good no leaks on the floor.