Looking for a Set of Good Cylinder Heads

M

mark sawyer

New member
Aug 20, 2015
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Hi everyone,

So I recently burned a valve in my motor due to a piece of dried JB Weld wedging in between the valve and the seat as mentioned in an earlier thread.
Unfortunately, the machine shop that has my heads has a large backlog related to COVID, and it does not look like they are going to be able to get my
heads back in time for some travel we have planned over the Thanksgiving holiday. If anyone might have a spare set of rebuilt heads, or a known good
set of used heads available, I would be very interested. Closer to Dallas, TX the better, but if someone would be willing to ship, I would be
interested in that too. Am willing to buy outright, or possibly a trade for my heads once they are fully rebuilt...

Would also appreciate any input or leads on a source for a head that is available ASAP.

Thanks

Mark
--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
So I found a guy selling a used set of "G" heads on fleabay... Only thing is he said he had a broken head bolt and when he repaired it, he went ahead
and changed to a set of Edelbrocks...

https://www.ebay.com/itm/114464891526?ViewItem=&item=114464891526

I was thinking about going ahead with these to get me on the road, but now that I've thought about it more, I'm concerned when the guy ran it with a
broken head bolt it could have warped the heads.... I'm guessing that rusty spot near that outboard headbolt in the pics is due to coolant leaking
out and pooling there?

What do you all think? Bad idea cause they could be warped? Or am I being paranoid?

Also, does anyone know are the "G" heads any better or worse than the stock "Js"? I believe these are small valve, same as the "Js"....

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
You pays your money and you take your chances. G head is a generic 455 use and suppose to have big valves in usual application and they are 80 CC. You will need to check them over and they may need some machine work to make them usage.

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

>
> So I found a guy selling a used set of "G" heads on fleabay... Only thing is he said he had a broken head bolt and when he repaired it, he went ahead
> and changed to a set of Edelbrocks...
>
> https://www.ebay.com/itm/114464891526?ViewItem=&item=114464891526
>
> I was thinking about going ahead with these to get me on the road, but now that I've thought about it more, I'm concerned when the guy ran it with a
> broken head bolt it could have warped the heads.... I'm guessing that rusty spot near that outboard headbolt in the pics is due to coolant leaking
> out and pooling there?
>
> What do you all think? Bad idea cause they could be warped? Or am I being paranoid?
>
> Also, does anyone know are the "G" heads any better or worse than the stock "Js"? I believe these are small valve, same as the "Js"....
>
>
> --
> Mark S. '73 Painted Desert,
> Manny 1 Ton Front End,
> Howell Injection,
> Leigh Harrison 4bag and Rear Brakes,
> Fort Worth, TX
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Looking at the pictures the manifold is not useable as it is a standard rise and not the low profile. If you get the entire package you could sell the manifold to some olds junky.

JR Wright

>
> So I found a guy selling a used set of "G" heads on fleabay... Only thing is he said he had a broken head bolt and when he repaired it, he went ahead
> and changed to a set of Edelbrocks...
>
> https://www.ebay.com/itm/114464891526?ViewItem=&item=114464891526
>
> I was thinking about going ahead with these to get me on the road, but now that I've thought about it more, I'm concerned when the guy ran it with a
> broken head bolt it could have warped the heads.... I'm guessing that rusty spot near that outboard headbolt in the pics is due to coolant leaking
> out and pooling there?
>
> What do you all think? Bad idea cause they could be warped? Or am I being paranoid?
>
> Also, does anyone know are the "G" heads any better or worse than the stock "Js"? I believe these are small valve, same as the "Js"....
>
>
> --
> Mark S. '73 Painted Desert,
> Manny 1 Ton Front End,
> Howell Injection,
> Leigh Harrison 4bag and Rear Brakes,
> Fort Worth, TX
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Most notable about the G heads that I have on a scrap engine (the block is junk) is that they only have rotors on the exhaust valves. They are also
not complete.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
PM sent about possible contact.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
> Most notable about the G heads that I have on a scrap engine (the block is junk) is that they only have rotors on the exhaust valves. They are
> also not complete.
>
> Matt

Would not having rotators on the intake valves be worth swapping out the retainers for my existing J heads?

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
> > Most notable about the G heads that I have on a scrap engine (the block is junk) is that they only have rotors on the exhaust valves. They
> > are also not complete.
> >
> > Matt
>
> Would not having rotators on the intake valves be worth swapping out the retainers for my existing J heads?

Mark,

Obviously they could run without them, but they are there for a reason. As nearly as I know, there is no reason you could not. What I do not know
without doing a lot of work is if the spring pockets in the head had to be cut deeper to keep the spring height the same. Unfortunately, I am very
time restricted these days. If you can't do better, I will see what I can do. I know that shipping from Michigan will be a consideration.

Good Luck

Matt Colie
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
> Hi Mark
> I emailed you a few days ago about a set of ready to go heads in
> Weatherford. I don't understand why you didn't reply. You could've been
> up and running by now.
>
> >
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Billy, that was my fault... I forget the forum is a mirror of the email list, and while I was monitoring the forum, I had not checked my email for a
few days... I finally did see your email (and ones from several other people looking to help) last night. I assume you meant the heads Boyd Mooney
had... I actually got in touch with Boyd based on your email and one he sent as well and purchased the heads from him this morning.... Working on
getting them installed now.

Thanks to you both and to all the others who reached out to me looking to help. Again, this proves to me the best part about owning a GMC is the
community behind it!

For those that are interested, the heads Boyd had were Ka castings, with a set of Comp Cams chromoly (Magnum) roller tip rockers. From my research so
far, I need to pick up a set of .150" longer chromoly pushrods (Apparently, they say to use chromoly pushrods since the rockers/pushrods are located
using guide plates) which are available from Comp Cams part # 7841-16.

The rockers themselves are part # 1442-16 or 1442-KIT which includes the guide plates and pushrods as a kit. I was concerned about running roller
rockers as they are not really needed on a low rpm motor, and I've heard they are not as reliable as regular rockers.... However. from looking on the
internet, this setup looks to be pretty reliable and the same rockers are used on kits for AMC and early Ford Windsor motors, so I'm going to give
them a shot.

Also kind of curious to see if I notice a difference with the roller rockers and the big valve Ka heads vs my old Js.... The J heads I had were stock
except for stainless exhaust valves. The rest of the motor is set up with higher compression pistons (runs well on mid-grade, but pings on regular) a
mild RV cam, Howell fuel injection and headers, which I think will work well with these heads. If all goes well, I'll respond back here with
impressions when I get back from our trip. We are (again, with luck) supposed to head down to Big Bend for Thanksgiving towing our 4cylinder
Wrangler. Should be a good test of the new heads, with some hills and altitude (near sea level here, to 4500 in Alpine) thrown in for the trip.

Thanks again to everyone who offered to help... Especially Billy and Boyd who hooked me up with a set of heads locally!

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
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