Need help with Vortecs

[rdalley]

I know this probably isn't the right forum, please forgive me.

I just built a mild 355 with Vortec heads for my 64 Chevelle and I cant get the headers to seal for the life of me. Has anyone been through this and can anyone recommend a specific gasket that will seal the rounded square exhaust ports on the heads to the oval ports on my headers?

I have tried several types, aluminum, copper, etc with no luck.

[ccracin]

The secret to any good seal is flat, true surfaces. Gaskets can only bridge so much gap. Make sure the head surfaces are clean, and flat. Use a steel scale or straight edge to check it. Dim the lights and put a small flashlight on the back side of the straight edge. If you can see light between the straight edge and the head it is not flat. This is usually not the problem. If it is use can try the trick below, but I would recommend a machine shop.

On the header you can try the straight edge. In most cases it is just as easy to get a large flat file and run it long ways back and forth on the mating surface of the header flange. You will then see if you have high and low spots. If you do, keep going until it is flat.

If you get both surfaces flat, you can almost use no gasket and it will seal.

I know this is not the most high tech way of doing this, but it has worked every time in my and alot of my friends cases. Good luck, I hope this helps.

[ElkyZO6]

Have you tried the factory metal one's for those heads?

[jjmontess]

I am running Vortec heads and have tried every gasket to seal them. The absolute best is Earls Performance Master Header Seals from Summit Racing. They are an aluminum gasket with graphite inserts. The graphite is very soft and seals great to non-flat surfaces. I'm running 12 year old headers that aren't perfectly flat and have no trouble with leaks.

[rdalley]

Originally Posted by jjmontess

I am running Vortec heads and have tried every gasket to seal them. The absolute best is Earls Performance Master Header Seals from Summit Racing. They are an aluminum gasket with graphite inserts. The graphite is very soft and seals great to non-flat surfaces. I'm running 12 year old headers that aren't perfectly flat and have no trouble with leaks.

Thanks, thats what I was looking for. Summit has a 1.36" and 1.5" square port and a round port. Do you know which you have?

[DaleLee]

You may take a look at Remflex gaskets... I use part # rf2006.

[SLO_Z28]

http://www.percyshp.com/Seal4Good.html

Those are the only gasket ive found that will seal if the mounting flange is bent. I had a set of 30 year old custom headers on my Z and it leaked like no tomorrow no matter what I used, when those first came out I bought a set and used them for years.