Head gasket recommendation request

[larry engelbrecht]

Hi folks. I just picked up my heads from the local machine shop after unsuccessful removal of the last three remaining exhaust bolts - or what was
left of them anyway. Which specific head and intake gaskets (I also will need to buy crossover block off plates). Both head and exhaust faces have
been resurfaced and I do have the Remflex gaskets to go with resurfaced exhaust manifolds, so everything is nice and flat.

It's been 30 years since I last built a Pontiac V8. I had really good luck with Fel-Pro print-o-seal something or other head gaskets, but there must
have been newer developments in gaskets since then. Any specific make and perhaps model number of parts for the Olds 455?

Thanks in advance.
--
Larry Engelbrecht

San Diego, CA

'73 26' ex-Glacier

TZE063V100319 03/07/73

 

[a.]

> Hi folks. I just picked up my heads from the local machine shop after unsuccessful removal of the last three remaining exhaust bolts - or what was
> left of them anyway. Which specific head and intake gaskets (I also will need to buy crossover block off plates). Both head and exhaust faces have
> been resurfaced and I do have the Remflex gaskets to go with resurfaced exhaust manifolds, so everything is nice and flat.
>
> It's been 30 years since I last built a Pontiac V8. I had really good luck with Fel-Pro print-o-seal something or other head gaskets, but there
> must have been newer developments in gaskets since then. Any specific make and perhaps model number of parts for the Olds 455?
>
> Thanks in advance.
http://www.appliedgmc.com/prod.itml/icOid/799
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[LQQKatJon]

I can only say what I know about the intake gasket/blockoff plate. I would buy the blockoff plates and gasket kit from applied, dick patterson, or
from JimB. They may all be the same item, but then you have a known working blockoff plate. all 3 will provide the intake gasket with the blockoff
plate. I know the intake gaskets that work, and can be bought locally, but I do not know or need to know how they come up with the size and
thickness of the blockoff plate, one of those I would just order from the vender.

If I had my heads and manifolds machined, I would buy Lenzi's copper gaskets, and skip the remflex. I think that is a better setup. the remflex
are good for manifolds/heads that are in not perfect machined shape. I am sure they will work perfect, but I have had some remflex failures, and I
think Lenzi's are more of a permanent repair, if your heads and manifolds are machined. Just my opinion on dealing with my gasket headaches and
talking to other owners.


--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[Jim Hupy]

There is an issue with re-assembly of a 455 Olds after the heads have been
machined on all surfaces. If you cut the intake manifold side of the heads,
the intake manifold will sit lower on the intake valley. Also, if the
compression surfaces of the heads are cut, and a thin steel gasket is used,
two things could happen. The heads will sit lower on the block and
therefore closer to the camshaft. As the Olds has a non adjustable valve
train, the pushrods will open the valves a bit earlier and further than
before the heads were cut. USUALLY NOT A PROBLEM, BUT, IT IS A GMC, AND
"STUFF" HAPPENS when you work on one. So for this reason, I use a
composition,"sandwich" gasket, which is thicker than the steel one, to make
up for the difference between cut and uncut heads. The second part of this
scenario, is when the heads are cut, and a thin gasket is used, the ends of
the intake manifold sit closer to the block, sometimes so close that the
end seals will no longer work because there is so much squish that the
seals will squirm out from under the manifold when you tighten the
fasteners on the manifold, and will leak a bunch of oil. This crush space
needs to be carefully measured by dry fitting the manifold and checking the
end spaces. Compare the thickness of the seals to the available space and
if there is not enough space, do not use the seals. Use a bead of HTV
SEALANT instead. I prefer Permatex "The Right Stuff" one minute gasket.
Comes in a caulking tube. Gotta work quickly with it.
Just what I would do. Your bucks, spend them as you see fit.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> I can only say what I know about the intake gasket/blockoff plate. I
> would buy the blockoff plates and gasket kit from applied, dick patterson,
> or
> from JimB. They may all be the same item, but then you have a known
> working blockoff plate. all 3 will provide the intake gasket with the
> blockoff
> plate. I know the intake gaskets that work, and can be bought locally,
> but I do not know or need to know how they come up with the size and
> thickness of the blockoff plate, one of those I would just order from the
> vender.
>
> If I had my heads and manifolds machined, I would buy Lenzi's copper
> gaskets, and skip the remflex. I think that is a better setup. the
> remflex
> are good for manifolds/heads that are in not perfect machined shape. I am
> sure they will work perfect, but I have had some remflex failures, and I
> think Lenzi's are more of a permanent repair, if your heads and manifolds
> are machined. Just my opinion on dealing with my gasket headaches and
> talking to other owners.
>
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[LarryW]

> There is an issue with re-assembly of a 455 Olds after the heads have been
> machined on all surfaces. if the
> compression surfaces of the heads are cut, and a thin steel gasket is used,
> two things could happen. The heads will sit lower on the block and
> therefore closer to the camshaft. As the Olds has a non adjustable valve
> train, the pushrods will open the valves a bit earlier and further than
> before the heads were cut.

Jim,
You are talking about a change in lifter preload. IIRC, the lifters will simply let the pushrods push deeper into the lifter, thereby not changing
the duration or lift. If the pushrods go to deep into the lifter trying to makeup for the material cut off of the heads, they may actually bottom out
the lifter, holding the valves open, loosing compression and maybe an engine that will backfire through the carb or out the exhaust. In either case
an engine that would not run very well and depending on how many cylinders it effected, it might not run at all. I experienced the phenomena on a new
engine who's preload was set to tight because of to long of a pushrod for the rocker assembly being used, loosing compression in one cylinder and
exhibiting itself as a miss. Compression test showed 25lbs on that cylinder, and cylinder leakage heard air coming out both throttle body and exhaust.
Placing a .030 shim under the rocker arm pedestal brought back compression and cured the miss. Just what I've experienced.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Jim Hupy]

Larry, like I said. It is a GMC, and stuff happens. I know the cures for
all of that, as do you, but not all who work on these beasts are so well
informed. Many think, "Hmm, I will just shave some off the heads, make more
compression and power". Often the reverse is true. These engines have for
the most part all been worked on before, been cut a bit here, a bunch
there, it all adds up to cascading failures once in a while. Jus' sayin'.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> > There is an issue with re-assembly of a 455 Olds after the heads have
> been
> > machined on all surfaces. if the
> > compression surfaces of the heads are cut, and a thin steel gasket is
> used,
> > two things could happen. The heads will sit lower on the block and
> > therefore closer to the camshaft. As the Olds has a non adjustable valve
> > train, the pushrods will open the valves a bit earlier and further than
> > before the heads were cut.
>
> Jim,
> You are talking about a change in lifter preload. IIRC, the lifters will
> simply let the pushrods push deeper into the lifter, thereby not changing
> the duration or lift. If the pushrods go to deep into the lifter trying to
> makeup for the material cut off of the heads, they may actually bottom out
> the lifter, holding the valves open, loosing compression and maybe an
> engine that will backfire through the carb or out the exhaust. In either
> case
> an engine that would not run very well and depending on how many cylinders
> it effected, it might not run at all. I experienced the phenomena on a new
> engine who's preload was set to tight because of to long of a pushrod for
> the rocker assembly being used, loosing compression in one cylinder and
> exhibiting itself as a miss. Compression test showed 25lbs on that
> cylinder, and cylinder leakage heard air coming out both throttle body and
> exhaust.
> Placing a .030 shim under the rocker arm pedestal brought back compression
> and cured the miss. Just what I've experienced.
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[chris tyler]

Historically Ive used Felpros for the most part for heard gaskets. The permatorque gaskets have a teflon coating, are fairly thick and forgiving to
minor imperfections.
Have you cleaned and checked the block deck surface?
I always go back and retorque after running though

Lately Ive been a convert to Cometics multi layer steel gaskets with spray copper sealant for hi po engines. But you won't go wrong with Felpro
--
76 Glenbrook

 

[jon payne]

Guys,

I just went through having both cylinder heads rebuilt earlier this summer. I spoke with Dick Paterson extensively before having my heads done and
finding the right machine shop that can do the work correctly, as Dick does . One thing Dick explained to me The original head gaskets where a
shim steel gasket measuring ~0.017". As this style gasket is no longer available he uses and recommends Fel-Pro head gasket. Problem is Fel-Pro
gaskets measures around 0.041 which means you need to shave the heads approximately 0.024" to get back to the stock height and compression. So if
your cylinder heads have never been removed you are in the same situation as I was in. I would suggest you talk to Dick he's very nice and will be
happy to help you if you have any doubts. Note if your cylinder heads have been removed before and machind then the machine shop you are using will
be able to measure the height of your cylinder heads and from there you'll know if you need to remove any more material from the heads.

Jon
--
Jon Payne
76 Palm Beach
Westfield,IN

 

[espen heitmann]

Jon the Fel-pro will compress a bit, not much but still..
Anyways the 70s steel gaskets are long gone for most makes and a little bit thicker gasket usually does not make any noticeable difference.
And stay away from the Victor reinz gaskets as they have a really bad fit, made a video to show how bad they really are, I only use Fel-pro on the
engines I build
--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway