recommended 455 valve cover gasket

[LQQKatJon]

did some quick searching and did not find what I was looking for, sorry if this is a repeat.

Have some spring work, that is going to include replacing the exhaust manifolds with headers, and it will be getting a new exhaust system. I am also
going to replace my oil dipstick tube, and relocate the tranny dipstick to the front hatch.

While I am at it, I am going to replace my valve cover gaskets, since I believe they are leaking slightly. So I ask What is the recommended method,
and/or gasket/sealant combination to use for the 455.

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

 

[Carl Stouffer]

Jon,

You'll want to use a rubber valve cover gasket. There is a 'steel core' rubber gasket on Ebay that looks interesting.

You don't really need any sealant. If you DO use RTV, it will make them REALLY hard to remove at a later date
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[dennis sexton]

Jon
Like Carl I used a rubber valve cover gasket (FPP-1658, but may no longer be available) I just used a little oil on each side.
I also used valve cover force spreaders, but you may need to use slightly longer bolts. And if you use a spreader on the bolt under the AC bracket you
may need to grind the bracket for clearance.

Example
https://www.walmart.com/ip/VALVE-COVER-SPREADER-BARS-4-BLACK-FINISHED/973893302?wmlspartner=wlpa&selectedSellerId=837&adid=22222222228144195373&wl0=&wl1=g&wl2=m&wl3=253427111225&wl4=pla-418851192878&wl5=9013542&wl6=&wl7=&wl8=&wl9=pla&wl10=112343835&wl11=online&wl12=973893302&wl13=&veh=sem

And - the valve covers are often bent from over- tightening, so flatten them before re-installing.

Dennis

> did some quick searching and did not find what I was looking for, sorry if this is a repeat.
>
>
> Have some spring work, that is going to include replacing the exhaust manifolds with headers, and it will be getting a new exhaust system. I am
> also going to replace my oil dipstick tube, and relocate the tranny dipstick to the front hatch.
>
> While I am at it, I am going to replace my valve cover gaskets, since I believe they are leaking slightly. So I ask What is the recommended
> method, and/or gasket/sealant combination to use for the 455.

--
Dennis S
73 Painted Desert 230
Memphis TN Metro

 

[Ken B]

Mahle (Victor Reinze) VS38305-TC

Currently on closeout at Rock Auto for $3.61

Rubberized Cork with steel stiffener.

The package says it fits both 403 and 455.

I just put a set on a 403. I lightly siliconed the valve cover side and used the bolts to line it up. Turned it over and let it sit on a flat
surface overnight to cure. (with the bolts still inserted to maintain alignment.)

Do not apply and sealer on the engine side when installed. That makes them easily removable and reusable in the future.

Use of the bolt spreaders is optional. Also available from Rock Auto under "tools". I did not use them but they are a great idea.

I ought to order an other set as a spare.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[rgogan]

My GMC Motorhome shop manual recommends RTV only without a gasket citing superior results and stating the factory stopped using the gasket for the
valve cover even though it is pictured in the manual. This is what I always used. I had a rebuilt engine put in 30,000 mi ago and now the valve cover
on the driver's side is leaking. Will let you know if the rebuilder used a gasket or straight RTV when I take it apart.

 

[terry1]

I've used same method as Ken since RTV came on the market, except I don't wait overnight. About 15 to 30 minutes will skin it and pin it to the cover,
unless it is a SBPITA cover that has to be finagled into place against gravity for long enough to get cramps in your hand. Definitely let it cure as
long as possible in that case. Almost always seal the gasket to the removable part/cover,unless it has a groove in its' design. Also notice that some
gaskets have small metal spacers embedded in them which will be disastrous if they get into the engine oil intake. Some of them will fit through the
screen! If you have to scrape the old cooked gaskets off, pack the whole internal area with clean rags before you pull the first piece off. Use a
reduced vacuum to carefully remove the wayward scraps from the rags before you pull them out. You might want to count them before and after
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[chris tyler]

What I have done for years is use a cheap cork gasket sprayed with 2 coats silver spray paint. This seals it and prvents it fronm absorbing oil.
Then glue it in plce with 3 m weatherstrip adhesive to the vlve cover and a coat of anti seize on the head side.
Never had one fail or leak yet, even when frequently removed to set the valves.
--
76 Glenbrook

 

[Jim Hupy]

The usual problem is that the hold down fasteners have been over tightened
at some point. Cork gaskets eventually will deteriorate over time, and
crack and leak. Then along comes someone with a socket and tightens them
some more. Remove the valve covers and scrape and clean every last little
bit of old gasket and cement from both surfaces. Sunday morning, going to
church, clean. Then using a very solid backup piece, straighten out all the
puckers created from the overtightening. Use a straight edge along the
sealing lip to check your work. Once that surface is straight, then use
your gasket of choice. Cork, composite, steel sandwich with silicone
ribbons, (my favorite) or silicone sealant, (my least favorite). Used in
the correct manner, all will work, IF THE COVERS ARE STRAIGHT.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> What I have done for years is use a cheap cork gasket sprayed with 2 coats
> silver spray paint. This seals it and prvents it fronm absorbing oil.
> Then glue it in plce with 3 m weatherstrip adhesive to the vlve cover and
> a coat of anti seize on the head side.
> Never had one fail or leak yet, even when frequently removed to set the
> valves.
> --
> 76 Glenbrook
>
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[Ken B]

The 403 that I am working on was seeping oil at both the front and rear of the covers. When I removed the valve covers I found that straight silicone
was used with no gasket. The silicone was coming loose on the ends causing the leaks. So the Mahle - Victor Reize gaskets is what I used.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana