So, when I bought my 69, it came with an extra 351w that came from a 74 I think.

Anyway, I took off a valve cover to cut out the center to fix a little valve lash. I was impaitient and wrecked a good cover .

Now, the rocker setup is a bit different and it looks like maybe this was a refresh and not rebuild based on what I see. I also see they did a bad paint job and painted with no tape, notice part of rocker arm and rod.

What are these rocker arms called? Looks like you can't adjust these as they are bolted in.

First picture is the current one in the stang with 3k miles on it, thoughts on how it looks after that?

 

Those are newer style rocker arms. And yes they just bolt on and sit on a pedestal. I have them on my 92 302 block in the 67 currently and have an extra set in my attic from my 87 302.

Look over by where the starter would be and post up the first portion of the casting number

 

Just looked, here is what I found. I don't know what the "AA-12" means though, any thoughts?

D4AE-6015-AA-12

D = 1970
4 - Decade Year - This is a '74 (Galaxie made 1959 through 1974)
A - Galaxie
E - Engine
6015 - part num


there is a date code there, "7 M 15"
which would be 1977, December 15th. But the "D4" is 74. What gives?

 

Casting number is a 74, first set of adjustable rockers are rail type, second set is non-adjustable pedestal type. Any noise on the second set would be due to wear or loose pedestals. Wear can be worn rocker arm, worn pedestal, worn pushrod, lifter, cam, or a collapsed lifter. The only scenario you can reliably fix without parts is if a pedestal (center bolt) is loose.

 

Rockers in the first pic are from the engine in the mustang. All those on the passenger side are completely tightened without any ability to tighten more. So, my thought is that it means hydrolic lifters? New to all this so I may be wrong or it's odd that all the rocker arms are completely tightened.


Looking at the D4AE, it's the cast and the date is the pour date. So, I hear 74 was the last high nickle mix in the 351w's. Looks like I missed it buy a few.

Now, I want to sell it or build it out with high HP. But now I am thinking I need to see the casting num on the one in the mustang. I was told it came from a 69 mustang, just not this one.

My 69 has
C9OE Date code 9k2
1969 Torino engine. October 2, 1969

So this looks to be the better one to build a beefy engine. I hate to rebuild an engine that was rebuilt 3k miles ago.

 

1. leave the engine that you currently have as is when you have a spare. drive it around like it is. If you want to build a beefy engine then build the other I'd say and drive around with the k nown good one. I've seen it too many times that people fool around with their current engine and end up with none

2. don't know if you figured that yet, the 1974 (D4) is the year they so to say came up with the casting. and that was then used for a few years, next one could be D9 for example. but anything that used that casting got that D4 stamp (to identify it) and then the date code when it was actually made.
So it's a 1974 casting produced in december 1977. The AA12 is revision number, basically whenever they see something they could improve with the casting they increase the revision number. But noone can really tell what's the difference between them I guess.
The "A" for galaxy is not always true. _Plenty_ of mustangs use DxAE/DxOE blocks, probably nearly all of them. This does not mean it came of a Galaxy or Torino.

3. the one you have 1st pic is studmounted head, the other one is pedestal mounted head. Either of those have their advantages.

4. what's wrong with the engine you currently have? I mean it could be good to leave that in the car since it could be from same year mustang?

 

Nothing is wrong with it, it's plenty strong, I have no idea of HP. I just have the spare and thought hmm, BEEFY!!

The spare although I see new parts in it, it's not looking as nice as a rebuilt should but I can only see under the valve cover at the moment. All other gaskets looks new so I believe at the least, it's a refresh. The previous owner said it was a rebuild. Now, if I paid for a rebuild and saw that paint on it and saw the rods and part of rocker painted, I would go through the roof. What's going to happen if that paint comes off and possibly clog something...

I think I need to pull the rods and rocker arms and clean them. With those rocker arms, do I have to adjust for valve lash and get TDC when adjusting or can I just pull them and put in where the cam is since you can't ajust those rockers??????

Thanks

 

don't pull it apart, just use a cloth with somethign that'll remove paint. If something flakes off you most likely will find that then in the oilfilter. I can't see any paint in the pictures, so I'm not worroed.
To adjust them you have to go through thenm manually (TDC) and set them or do it with engine running. But in any case you'd have to loosen tighten the rocker nuts and for that alone replace them again. I'm not really sure that you're just making yourself more work or just create problems you never had.

Kalli