Oil Pan Bolts and Muffler

[67step100]

When I was removing the 18 bolts holding the oil pan I thought they were all the same length and just dropped them into a can. Now I notice two of them are a bit longer than the rest. Where would these two longer bolts go? I was thinking the two holes closest to the transmission housing (one each side of pan) but I don't know. The engine is a 318.

I had to drop the muffler so I could shift it over enough to get the pan out. The ends of the muffler where they bolt to the exhaust manifold are bell shaped and there is a white substance on the manifold side. Looks like it is some material to make sure there are no air leaks when they are bolted together. What is this material? It has hardened and some of it has broken away so I wanted to replace it but I don't know what it is.

Thanks again for the assistance.

[PwrWgnDrvr]

I would put the longer bolts into the aluminum timing cover. There is often a donut style gasket in the exhaust that is a heat tolerant composite material.

[martincom]

The longer bolts would go into the aluminum timing cover. Aluminum threads don't have the strength of steel. Thus, they are longer to spread the load across more threads.

The exhaust donuts are made from a composite fiber (probably asbestos back in the day) or steel. I prefer steel when installing a new exhaust system. Once used, the flange has been deformed enough whereas steel will not seal it.

[67step100]

Thanks. Longer bolts went into the timing cover.

I chipped away the plaster type gasket (wore a respirator in case it was asbestos) on the muffler and installed a fibre gasket that had a copper or brass core. Sealed it up nicely.