Mismatched Heads Again

[Carl Stouffer]

About a month ago, I mentioned that I had discovered that my '75 455 had a J head on one side and a K head on the other side. The K head had a badly
burnt exhaust valve and needed to be replaced/repaired. For lack of a better option, I ended up getting a pair of K heads reconditioned and had them
installed by my very good, trusted mechanic. I feel kind of wimpy for not doing the job myself, since I know several of you who wouldn't hesitate to
do a valve job who are 10 - 15 years older than I am, but I am also not retired and had time restraints which made it more sensible to hire out the
job.

The weird thing is that as far as I knew, the engine on this coach was unmolested. Although the heads were different castings with different size
intake valves, they were painted the exact same color and both had the steel shim OEM type head gaskets under them.

Just curious to see if anyone has ever run into something like this before or if any of you GM guys have ever heard of anything coming out of the
factory like that.

http://www.gmcmhphotos.com/photos/misc-gmc/p63626-mismatched-heads.html

http://www.gmcmhphotos.com/photos/misc-gmc/p63629-p1020594.html

http://www.gmcmhphotos.com/photos/misc-gmc/p63629-p1020594.html
--
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

 

[jim kanomata1]

If your going to do heads, majority of the time your valve guides will be
worn so to replace the guides is not that simple unless you have the tools
in your shop.
Also check the spring tensions with a tool.
Oh, heads should be magnafluxed as there are always chance of cracks.

> About a month ago, I mentioned that I had discovered that my '75 455 had a
> J head on one side and a K head on the other side. The K head had a badly
> burnt exhaust valve and needed to be replaced/repaired. For lack of a
> better option, I ended up getting a pair of K heads reconditioned and had
> them
> installed by my very good, trusted mechanic. I feel kind of wimpy for not
> doing the job myself, since I know several of you who wouldn't hesitate to
> do a valve job who are 10 - 15 years older than I am, but I am also not
> retired and had time restraints which made it more sensible to hire out the
> job.
>
> The weird thing is that as far as I knew, the engine on this coach was
> unmolested. Although the heads were different castings with different size
> intake valves, they were painted the exact same color and both had the
> steel shim OEM type head gaskets under them.
>
> Just curious to see if anyone has ever run into something like this before
> or if any of you GM guys have ever heard of anything coming out of the
> factory like that.
>
> http://www.gmcmhphotos.com/photos/misc-gmc/p63626-mismatched-heads.html
>
> http://www.gmcmhphotos.com/photos/misc-gmc/p63629-p1020594.html
>
> http://www.gmcmhphotos.com/photos/misc-gmc/p63629-p1020594.html
> --
> 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
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[Carl Stouffer]

Jim, These were good cores with hardened valve seats. Larry's engine & Marine (Tucson) put them together with new SS valves, guides, and springs.
They had been milled about .010. The new gaskets were thicker than that plus the stock metal gaskets.
--
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

 

[jim kanomata1]

Ok, Most machine shops have a low paid young guy doing the heads. I always
request that the usual tech work on it and pay accordingly.

> Jim, These were good cores with hardened valve seats. Larry's engine &
> Marine (Tucson) put them together with new SS valves, guides, and springs.
> They had been milled about .010. The new gaskets were thicker than that
> plus the stock metal gaskets.
> --
> 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
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[Carl Stouffer]

These guys have a REALLY good head guy and they have done lots of Olds marine engines. So they know the Olds 455.

http://larrysengine.com/
--
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