340 Head Gasket info needed

[SS Lancer]

How thick would a factory headgasket be for a 1969 340 ?

 

[65Val]

How thick would a factory headgasket be for a 1969 340 ?

Factory would most likely be a steel shim gasket...probably ~ .020 thick....

 

[AJ/FormS]

I never measured them but .020 sounds about right

 

[pishta]

I think the red ones you can buy are about .020.

 

[SS Lancer]

Factory would most likely be a steel shim gasket...probably ~ .020 thick....

Thank you Sir

 

[RustyRatRod]

I never measured them but .020 sounds about right

So, in all the engines you've said you've built, you've never, ever, ever miked a head gasket while figuring compression ratio? I find that almost impossible to comprehend.

 

[65Val]

Thank you Sir

You're welcome!

 

[moparker]

The Felpro ones are .540. Make sure get the right thickness.

 

[nm9stheham]

The Felpro ones are .540. Make sure get the right thickness.

Typo above... .054"

Felpro 8553 types (the standard gasket kit ones) are the one referred to in that range of thickness; I've read .047" to .052" for that PN and measured right at .050" myself. IIRC, Felpro lists them at .051".

Felpro 1008's are .039".

Mr Gasket 1121G are .028"

 

[SS Lancer]

The Felpro ones are .540. Make sure get the right thickness.

Thank you Sir

 

[replicaracer43]

And cometic will make you whatever size you want, at a specific bore size, so you don't have crevice volume issues

 

[AJ/FormS]

The .028s started migrating into the valley on me, at 11.3 scr/185psi, with Eddies, in about one season. I caught them at the first annual winter inspection.
I have heard that others have had better success.
My case may have been a one-of.
I have had no trouble at all with re-using 1008s. They may be pricey to buy, but for me they have become the cheapest gaskets ever, in the big picture.

 

[americal]

With a thicker head gasket would you need longer push rods,

 

[AJ/FormS]

.011
I allowed for that in the original build, and I had adjustable arms.

 

[Wyrmrider]

not generally-but
(here comes the but)
what you want to do is set your mid lift geometry- shaft height which will determine your pushrod length (and shaft spacer thickness) and account for head and block milling and head gasket thickness and any angle milling