alsmith787

Hey Guys, it's time to replace the exhaust manifolds (they have hairline cracks & leak pretty bad) bought a pair of the free flow exact replacement exhaust manifolds from Fusick had them trued (surface ground) they're perfect! I'm leaving the heads in place but I am going to put exhaust gaskets on (Remflex 11-001) Question I have and always am lost in this area the manifolds are a 2 bolt exhaust flange set up connecting to the exhaust pipe is there a donut insulator or a gasket between the pipe connector & the manifold? & what should I buy if anything some readings day they just bolt up metal to metal this is confusing since there are these type of gaskets for sale what is the actual setup? Any suggestions would be appreciated 👍
thanks
Alsmith787

joe_padavano

The connection to the pipe is metal-to-metal. If you are worried about that, use a little Walker Acousti/Seal on the mating surfaces.

69 Hurst

What Joe said. I've also had great success using Permatex Ultra Copper on mine.

acavagnaro

I'm curious about the Fusick W/Z manifolds (I suspect they're Thornton castings but maybe I'm wrong), I've heard the reproductions don't have the center divider like the originals. Is that true? I find it interesting that every published picture of them shows the external side. Never a picture of the machined face so you can't see whether or not the divider is there.

joe_padavano

The whole point of the W/Z manifolds is that they are internally divided with separate "runners", not just a center divider. Do not confuse these with the small block manifolds they sell that have the appearance of a center divider but no internal runners. The small block manifolds don't physically have the room for internal runners.

FStanley

mmmm... interesting no one said to use donut between exhaust manifold and head pipe..


https://www.drivparts.com/part-detai...lange%20Gasket

OLDSter Ralph

Read Post #2

joe_padavano

Because it physically is not possible. The A-body manifolds have an integral conical seal that mates with the flare on the pipe. There is no way to use a donut. You will note that this page from the 1970 PIM only shows the use of a donut on the Chevy I6, not on the Olds V8s.







Contrast the shape of the outlet ports on the W/Z manifolds in the photo above with the outlet port on this full size manifold in the photo below. The full size DOES use a donut.