Small Block Heads

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brian6pac said:
I have had 8 sets of T/A heads and most were U on top and J on the bottom.
The casting half's could be any combo of J, U, O, or a rare Z head
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So a "U" head is a T/A head! Thanks. I admit I have never worked with or even touched a T/A head. Is the only difference between an X head and a T/A head the valve guide angles. Like I said, I've never really messed with them.
 
harrisonm said:
So a "U" head is a T/A head! Thanks. I admit I have never worked with or even touched a T/A head. Is the only difference between an X head and a T/A head the valve guide angles. Like I said, I've never really messed with them.
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The T/A head had the intake push rod moved and used an offset intake rocker. As far as I know all factory small block heads share the same valve angle.
 
harrisonm said:
So a "U" head is a T/A head! Thanks. I admit I have never worked with or even touched a T/A head. Is the only difference between an X head and a T/A head the valve guide angles. Like I said, I've never really messed with them.
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No not necessarily, the T/A heads were also J heads. The letters don't mean much as far as I can tell, if someone has an answer that would be great but like I said they could be any letters or combination of letters. Here are a couple T/A heads that are J's top and bottom.

030.JPG


038.JPG
 
brian6pac said:
The dates are 02100 and 03110 so Feb 10 70 and Mar 11 70, one month apart.
Only 68, 69 X heads have 340 on them, all other 70 & up J,U,O,Z, heads have 360 on them.
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The reason I say I disagree is because you're wrong. There are j&u heads made after 1970 that do not have 360 cast into them. I'm sorry if this upset you that you are incorrect and I called your attention to it.
 
brian6pac said:
This is to Jadaharabi, So you disagree with what?
I think that if someone disagrees they should explain why.
We all might learn something, I'm definitely not perfect and I always want to learn so could you please explain!
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See post 33
I'm sorry you're so upset that I disagree with you.

I am assuming that you are referring to the 360 cast onto the intake Port under the valve cover that is what I'm talking about anyway.
 
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Jadaharabi said:
See post 33
I'm sorry you're so upset that I disagree with you.

I am assuming that you are referring to the 360 cast onto the intake Port under the valve cover that is what I'm talking about anyway.
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I'm not upset, I just don't know what you disagree with. There was more than one thing on that post that you could disagree with and without knowing what that is I can't say yes or no to your comment. I have probably 15 sets of X heads & J heads right now and have had probably more than 50 sets over time and I don't know what you are saying. If they don't say 360 what do they say? Do you have a picture because I have never seen one. What years?
I know Chrysler have done some strange things, could be casting plant some where, west coast? I'm on east coast so maybe I just never seen one.
 
brian6pac said:
I'm not upset, I just don't know what you disagree with. There was more than one thing on that post that you could disagree with and without knowing what that is I can't say yes or no to your comment. I have probably 15 sets of X heads & J heads right now and have had probably more than 50 sets over time and I don't know what you are saying. If they don't say 360 what do they say? Do you have a picture because I have never seen one. What years?
I know Chrysler have done some strange things, could be casting plant some where, west coast? I'm on east coast so maybe I just never seen one.
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At the Indy cylinder head swap meet last March I sold two J heads. They were dated a month apart one of them just had the head number the other had the 360 cast on top of the intake Port under the valve cover. Both had the 1.88 intake valve. The guy that bought them did not care that one said 360 and the other one did not.
So what I am disagreeing with is your statement that after 1970 the J heads all had 360 cast on them.
 
Can't you just go by the casting number?
 
4spdragtop said:
Not for TA heads. I believe they have same casting number as X heads.
I could be wrong tho.
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I dont think the TA heads were the same casting number as X heads. I think they were the same as the late 340 J heads / 360 heads.
As far as the origninal question, I wouldnt hesitate to mix and match the heads for a street engine.
 
TA heads are not the same casting as the X head...they are basically J heads or wait...O...or U heads...has 360 casted into the head under the valve cover....TA heads share the same casting number as the J head....but are listed under a different part number due to the intake pushrod being drilled at an angle,,,,so stock they offer no performance increase of the standard head but they come with their own rocker arms....

many time on Ebay you will see someone advertising TA heads but the intake pushrod is not offset.....that is becuase they are the same casting number....and they dont know how to tell them apart.
 
I think they were all '70's era J, U or O. IIRC there were never any X T/A castings as these were the early 68's and possibly ran out before the T/A design started. Of course there may be some weird examples.
 
Hi All,

I don't know if this is the right section to ask....
But here I go.. I have a 66 plymouth Barracuda with rebuilt 273. Come to find out the that one of the heads(cast iron original) has a crack in it. So..... What type of performance heads are out there that I can basically purchase and will bolt right on as a replacement. I also installed headers(doug headers) so i want to make sure the heads will work with this application as well. Just to clarify, i"m no mechanic but i would greatly appreciation some suggestions. I want to make this as painless as possible once i switch the heads out.

Thank you all
 
I don't think there is a direct bolt head on for a 273, the bores are to small for the big valves.
You probably want to go to parts wanted and post a ad for the head you need.
 
Quick question
I neee to identify my Heads on a 72 340 block.

I’m familiar with j heads from another car.

These heads say “l”

What do I have? Thanks in advance everyone
 
Garth B said:
Quick question
I neee to identify my Heads on a 72 340 block.

I’m familiar with j heads from another car.

These heads say “l”

What do I have? Thanks in advance everyone
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I prefer to identify head casting by their casting numbers. 915 in the case of T/A heads, which were 360 heads machined differently. Pics also can help. 915 were also used on '72 340's.

I may have read somewhere why some heads are J, O, U, etc. But I don't recall what the theory was.
 
harrisonm said:
So a "U" head is a T/A head! Thanks. I admit I have never worked with or even touched a T/A head. Is the only difference between an X head and a T/A head the valve guide angles. Like I said, I've never really messed with them.
Click to expand...

894 heads are X heads only with only 2.02" intakes. They are a different casting, but similar specs to 915. The pushrod holes were machined differently in the T/A 915 heads to accomodate the offset rockers. LA engine guides are all the same.
 
Garth B said:
Quick question
I neee to identify my Heads on a 72 340 block.

I’m familiar with j heads from another car.

These heads say “l”

What do I have? Thanks in advance everyone
Click to expand...
Can we get a picture Garth?
I don’t remember an “I” casting, just the above X, O, U & Z letters. The letters were cast in on each side of the head and could be cut off a tad.
 
U is a casting
pushrod machining makes a head a 6 pac head- rare
u can have the same casting machined standard- most are
 
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