Slant 6 head interchange: 1975 head on 1969 Block?

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Val69_170

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Hey,

I bought a 1969 Valiant and the 225 head is junk, cracked and burnt valves.

I found a 1975-78 225 Head casting #3698447 on Ebay rebuilt with valves from a business for $210 shipped.

The guy at the shop selling it said I need to check to see it it will fit my block. He said my engine is earlier model. When I take out the spark plugs it has tin tubes surrounding them. He said to check if they are "large tubes"

The head they are selling doesn't have tubes? I don't get what I need to check. I bought a Haynes manual that covers 1967-76 Dart & Valiant 6 cyl.

Will this head work on my block is the question?

Thanks,
 
I wouldn't necessarily call a '69 block early. Any slant 6 head with the solid lifter setup will fit any earlier slant 6 block. The heads are the same for any block size. There were some changes in later years to the spark plug (which still works fine). The heads eventually went to hydralic lifters. These heads will also physically bolt on but won't work without some extensive oil passage mods (I think-never tried it). Also, around '67 (maybe) there was a slight change to the combustion chamber, but that works fine either way as well. Most believe that the later chamber design is better.
 
The short and correct answer is that the head you're looking at will fit and work fine on your '69.

Throw the Haynes book in the trash. It's worse than useless; it will mislead you with wrong information. Get the three books described in this thread as quickly as you can.

Aaaactually…Polkat's info is a little crossed up. The heads do not contain the lifters. All slant-6 heads bolt onto all slant-6 blocks. The '81-'87 heads used on blocks originally equipped with hydraulic lifters require their own special valve cover, but that's the only point of potential adaptation required. The '60-'66 heads have a less refined combustion chamber; the '67-up heads have a better chamber shape for more complete combustion. The '60-'74 heads have aluminum tubes around the gasket-seat spark plugs. '75-up heads do not have spark plug tubes and use taper-seat plugs for which fewer options are available. There is no "large tube" vs, "small tube"; it's with vs. without. Many '72-up heads have an extra bolt-and-flange port at the rear of the manifold mounting face. This is for air injection, an emission control system used on some vehicles starting in '72. The extra passages in the head for air injection make the head heavier by about 20 pounds, and if your car hasn't got air injection you need to block off the extra flange port.
 
Thanks Everyone,

I think for the price it's a good deal to get me up and running.

Right now even with the bad head she runs, five cylinders.... but, I drove it 200 miles to my brother's garage to work on it, didn't run that bad.
 
Sorry, I didn't mean that the lifters were in the heads (they are obviously in the block). But it was my understanding that the old blocks didn't carry enough oil through the lifter galley for hydralic's to work. Is that wrong?
 
The difference is in the rear cam journal/bearing (fully grooved on the hydro motors to supply more oil to the rocker shaft, then from there through the rocker arms, down through the pushrods, and into the lifters). So if you are retrofitting solid-lifter engine to run hydro lifters you have to groove the rear cam journal or bearing and install the hydro rocker shaft, rockers, pushrods and lifters. But no, there's nothing about the block that impedes enough oil flow to preclude the use of hydro lifters.
 
Val69_170, sorry, didn't mean to hijack your thread. Dan, thanks for the info! I'm learning (trying to anyway). I guess the real question is if, other then no longer having to do adjustments, is there any real advantage to running hydralic lifters in a street/strip car? I'd think the solids would perform better. I won't butt in anymore!
 
polkat said:
Val69_170, sorry, didn't mean to hijack your thread. Dan, thanks for the info! I'm learning (trying to anyway). I guess the real question is if, other then no longer having to do adjustments, is there any real advantage to running hydralic lifters in a street/strip car? I'd think the solids would perform better. I won't butt in anymore!
Click to expand...

I have read extensively on this board and the .org board and I have yet to hear ANYONE say a single good thing abiut the /6 hydraulic lifters/setup.

If they have any advantages (except the fact that they only have to be adjusted once) I don't know what it is....
 
Bill Dedman said:
I have read extensively on this board and the .org board and I have yet to hear ANYONE say a single good thing abiut the /6 hydraulic lifters/setup.
Click to expand...

There's nothing the matter with it. It's an unusual design but works fine and reliably. The only problem is a relative lack of off-the-shelf cam grind options. If you want a better-than-stock cam, you need to do some extra work in specifying the grind with a competent cam grinder, after talking to highly experienced experts like Doug "Doctor Dodge" Dutra over on slantsix.org .

If they have any advantages (except the fact that they only have to be adjusted once) I don't know what it is....
Click to expand...

There's not even an initial adjustment. The rockers aren't adjustable; they don't need to be.
 
slantsixdan said:
There's nothing the matter with it. It's an unusual design but works fine and reliably. The only problem is a relative lack of off-the-shelf cam grind options. If you want a better-than-stock cam, you need to do some extra work in specifying the grind with a competent cam grinder, after talking to highly experienced experts like Doug "Doctor Dodge" Dutra over on slantsix.org .



There's not even an initial adjustment. The rockers aren't adjustable; they don't need to be.
Click to expand...

Thanks for the insight. I don't think I'd be interested in one...:sign10:
 
Are they the same lame rocker arms that are used with the solid lifter setup, which suffer from ratio-droop (1.37?) or are they a different design which might actually HAVE a 1.5:1 ratio?

If they DID, I could use them and some adjustable pushrods to achieve proper valve lift.

Any chance?
 
No, totally different rocker arm design. Don't know how accurate to nominal spec they are with respect to ratio.
 
Well, I don't mind adjustments on the solid lifter rockers, and there are a few good grinds out there for the solids, but I wasn't aware that the stock rocker ratio was so off. Is this common among them, or can you search out good ones?
 
Val69_170 said:
Hey,

I bought a 1969 Valiant and the 225 head is junk, cracked and burnt valves.

I found a 1975-78 225 Head casting #3698447 on Ebay rebuilt with valves from a business for $210 shipped.

The guy at the shop selling it said I need to check to see it it will fit my block. He said my engine is earlier model. When I take out the spark plugs it has tin tubes surrounding them. He said to check if they are "large tubes"

The head they are selling doesn't have tubes? I don't get what I need to check. I bought a Haynes manual that covers 1967-76 Dart & Valiant 6 cyl.

Will this head work on my block is the question?

Thanks,
Click to expand...
Go ahead and use the '75-80 head if you found a good deal on one. They have flash hardened seats so that would be an upgrade from the '69 head. Just remember to use the later, short reach, tapered spark plugs or things can turn ugly.......
 
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