Do you use gaskets with exhaust manifolds on a 440?

[Trench]

My motor is almost done and I do intend on using exhaust gaskets but i did notice the factory manual says they are not needed. What does the B Body community do? Gaskets, no gaskets, or gaskets and sealer like copper rtv?
I'm very interested to see what the opinions are here, and as always thanks in advance!

 

[snakeoil24]

If the manifolds are straight and not warped, no gaskets. If warped then chuck the manifolds or have them milled by engine shop. Confirm with a straight edge. If headers then use copper gaskets.

 

[69 Sleeper Bee]

If you had the exhaust manifolds planed at the machine shop you don't have to.

 

[furious70]

My frank answer is I've done about everything depending on the engine and exhaust. Nothing, copper rtv only, every kind of gasket, gasket plus copper rtv...

 

[moparsaver]

If headers

Remove and replace with manifolds with no gaskets.

 

[Billccm]

Use remflex gaskets. You won't regret it.

 

[MarPar]

Use remflex gaskets. You won't regret it.

I second this

 

[topside]

I'll add that in circumstances where I use a gasket in that location, I trim the spans of bridge material between the ports so they're not visible; improves appearance and access.
There's no reason to re-install a warped manifold - fix it beforehand, as already mentioned. On the drag car, I use the hi-temp silicone instead of a gasket, but if it had to come apart often, I'd use a gasket.

 

[steve340]

Cast iron manifold and heads - no gasket just a smear of high temp RTV on the sealing surface.

 

[440 PHIXX]

I’m not sure how much horsepower headers add but... I remember a few guys cutting half a second off the 1/4 ET.

 

[INTMD8]

Cast iron manifold and heads - no gasket just a smear of high temp RTV on the sealing surface.

Agreed.

 

[chtampa]

They are cast and will clean very easily on a large belt sander like heads cleaned up on.

 

[Hemirunner]

Ultra grey always worked for me

 

[mikerman]

My motor is almost done and I do intend on using exhaust gaskets but i did notice the factory manual says they are not needed. What does the B Body community do? Gaskets, no gaskets, or gaskets and sealer like copper rtv?
I'm very interested to see what the opinions are here, and as always thanks in advance!
View attachment 1303954

Done all that too many times
Stock cast manifolds, use 440 motorhome gaskets. Trim up if you like.

 

[snakeoil24]

No gaskets or rtv on mating surfaces

 

[KENTON]

Just bought a system from accurate exhaust, and they told me "make sure my manifolds were flat, and don't use gaskets, that's what cracks cast iron manifolds." So I just did what they said, and no leaks.