1970 Mustang 428 CJ part number needed

[Rory McNeil]

To be honest, I would not use any gaskets on a 428 CJ with exhaust manifolds. You will notice that the exhaust ports of the exh. manifolds are larger than the ports in the heads, I have never seen any exhaust gasket that will match the ports of the CJ exh, manifolds. As long as the mating surfaces of the heads and exh. manifolds are flat and smooth, there should be no leaks with putting it together without gaskets. Plus the solid fit without gaskets will greatly reduce the chances of cracking a valuable and hard to find factory CJ exhaust manifold. Like I said earlier, a skim of Nevr Seeze around the port openings will help prevent rusting surfaces down the road.
Are you doing this job with the engine out or in the car? If its in the car, I have never had much luck removing, or even worse trying to install the exhaust manifolds, with everything in place. I ended up re & reing the cylinder heads with the exh, manifolds attatched, and taking off the manifolds afterwards on the bench. Plus if you need to have the heads exhaust side re surfaced, they would have to be removed anyhow. Not the more fun engine compartment to work in! Good luck.