cracked 304 head

[OEM1984CJ7]

Well, I was wrapping up on the project and finally got the carb installed and all the gauges to start the motor and set the rings. Put water in the radiator and BAM on the right side rear corner water dripping

A crack in the head near the last rear head bolt. Soooo disappointed. The heads were built and fluxed I was told so wonder what would cause the crack? Improper torque patterns or ft lbs?

I guess I need to find another set of heads and start over. Anyone know if you can re-use the valley pan? I ordered a top end gasket set today and new ARP head bolts from Jegs. Getting the materials ready.

It was looking so nice also:

 

[jeepboy45]

Oh NO !! that sucks bad!!

I'd question whether the shop really magnafluxed them...

 

[Les]

Hmm.....I'm with Jeepboy45, in asking if the heads were actually magnafluxed by the shop you sent them to? If it wasn't cracked when it left the shop, they rarely crack as a result of being torqued down, unless someone who had absolutely no idea how to do it did the work, and had no idea what a torque wrench is for..... however, I'm going to assume that wasn't the case. They can also crack later, after a few heat/cool cycles, but since you haven't run the engine yet, one does have to return to the possibility of something fishy going on at the shop.

 

[mtnwhlr]

I would be taking them back and say WTF

 

[OEM1984CJ7]

Here are pics of the crack and the area it is located. The guy I bought the engine from said he never saw it and the machine shop that did the work closed its doors.

 

[jeepboy45]

wish I could help...
I HATE to see people lied to, and cheated.

I have a AMC 304 on a stand you could HAVE... But you are in Texas and I'm ---not so conveniently --- located in Fla... I'd mail you a head, but the shipping wouldnt be cheap!!

I feel your pain....
Hopefully going to turn the key this weekend on a 360 I just built....

Good luck...

brian

 

[mtnwhlr]

I think you can see why they closed there doors. Because of crappy work.
I feel for you.

 

[jeepboy45]

I think you can see why they closed there doors. Because of crappy work.
I feel for you.

Sounds more like NON-WORk... charging for things that were never done.

 

[OEM1984CJ7]

Thanks for the offer Jeepboy, I am in E. Tn area. I don't know what shipping would be.


Can you use different cast # on different year blocks? My cast # is 32333224 which shows 79-81 model. If I found a decent set from another year would they be the same as far as mounting and having machine work done and installing them on my 79?

 

[jeepboy45]

I dont believe there will be an issue.
However, if you happened to find ---and I doubt you will--- a set from 1973 or earlier, they will have different rocker set up. But those are more rare to see.

Here is a link with a lot of cool data.
amc engine casting numbers

I was mistaken about Texas, sorry....
I'm coming to East Tennessee, North Carolina in December. Wish it was sooner, and I could bring you a head!!!

Here's a guy in Chattanooga with a set of reworked heads. Might be kinda pricey though, but:
JEEP AMC 304 Heads

 

[OEM1984CJ7]

I found two sets.

One that was built a while back that needs rechecking or polishing? $100 set, Cast # 3231480-2 Which I think is a 1978

Or the other from the CL add that I talked to the guy and he will take $300 for the set and ready to bolt on. Cast # 3216086-1 which I think is a 1974 150hp heads bridged rockers and not single. He stated Dovers did the machine work in Chattanooga and they did have bridged rockers. Nice guy.


Can someone verify these are good cast numbers and they will work on my 79 block ? Was the only difference in HP the head used? They go from 210hp down to 130hp in 81.

thanks.

 

[jeepboy45]

look at the link I sent you regarding casting numbers.
I didnt see the 3231480-2 on the list.

You should have bridged rockers currently on your 1979.
I'd stay with those to avoid complications.


It would be nice to just bolt em on. If you get the cheaper ones, you should plan on a valve job, and surfacing. I just spent 130 on the valve job and 42 for surfacing. That is the price if no parts are needed. By the time you spend the money for labor and potential parts, you might as well get the finished ones. Just my opinion.

To get a GOOD set for $300 is probably the way to go.

 

[OEM1984CJ7]

Road trip today for the $300 set. He told me that he had the heads done and they put them in a heavy plastic bag with wd40 or some kind of oil. I thought wd40 had water in it and was not good for metal parts for protection and just for penetrating oil? He said there was no surface rust on the bottom section so we should be good. I will post a pic when I get them home today.