Spark plugs dont fit in new engine!!

[1FatPony]

I bought a new long block last weekend that is supposedly the exact same motor for my 87 mustang GT 5.0 HO. I went to kragens the other day and bought new plugs for an 87 mustang gt. I tried to put them in and they dont fit. Its like the threads are too deep. I looked at my old heads and they fit prefectly. The threads are closer to the opening. Whats wrong here!?!?!
New heads

Old Heads

 

[TomCat]

Got any casting #s off of the block or anything?

 

[poneypower89]

block wouldnt matter.. threads are in the heads.


LOL, honestly? It looks like you really need to take the paint off there and give urself some new room.

U sure those are e7 heads and the correct spark plugs?

 

[1FatPony]

it says 91 on one corner and I think S on the other corner of the heads. I am assuming my old heads were stock and I got the stock plugs and they fit into my old heads so something is wrond with these new heads

 

[TomCat]

I know the threads are in the head... I just wanted to get a feel for the engine in whole. The actual casting numbers on the head, if it's a E7TE, will be on the underside of the head near the lifter valley.

 

[1FatPony]

Is that the only way to find out what heads they are? I already have them bolted down and the intake manifold on.

 

[jgfiveoh]

model year part #/casting
1979-80(1) d9ae-6049-aa
82-84
85 e5ae-6049-ca
86 e6ae-6049-aa (2)
87-93 HO e7te-6049-pa (3)
e5te-6049-pa
1993 cobra f3ze-6049-aa (4)
e4ze-6049-aa

1) the 5.0L V8 was not used in 80-81 mustangs
2) thr e6ae cylinder head was also used in non-HO v8s in 86-91 this casting is also referred to as the truck head
3) the cylinder head carries either an e7te prefix or an e5te prefix, the former being the most common, this casting was also used on 94-95 HOs
4) this bare cylinder head is specified for engines built through 4/13/1993, and after that the part # was updated to the 94 service part# e4ze-6049-aa

check your heads out for the casting # (should be under the valve cover area or anywhere around it so u should see it) and see if it matches one from above then u will know what it is off. it could be and earlier casting of a 289/302/maybe even 351 head but i could not say for sure without checking.

also where did u get this engine from because the ones from the parts stores sometimes have a combo of different parts on them from what i understand.

check it out and let us know

 

[1FatPony]

the casting number is under the heads. My old heads say e7te.

 

[1FatPony]

I think I figured it out. I think they are 86 heads were the only year in which they used the deeper plugs to go further into to chambers.

 

[poneypower89]

edit because of stupidity.

 

[millhouse]

Just going off of the picture the new heads look different than the old. Those exhaust ports look tiny in comparison.

If indeed the engine was supposed to be an 87 h.o. longblock and turns out to be otherwise…..I'd ask for my money back.

 

[jrichker]

The 86 heads didn't breathe as good as the 87 and later heads, so you might want to consider reusing your old heads.

 

[1FatPony]

the exhaust ports are the same size. The old ones are just blacker and harder to see. What is the difference between 86 and 87 heads?

 

[bullitstang1313]

I believe that the 86's had a different size combustion chamber than the E7TE's. I'm not positive on this though.

 

[millhouse]

I believe that the 86's had a different size combustion chamber than the E7TE's. I'm not positive on this though.

I believe the combustion chambers were also a swirl port design (different than the e7's)

I personally wouldn’t stand for it. What's the point of buying a longblock if you need to put your old heads back on that probably need to be rebuilt.

Also, chances are if it is indeed an 86 then it also has flat top pistons. Putting on e7's may cause piston to valve issues. The cam is probably not a h.o. cam…so you'd need to swap that over too.

 

[1FatPony]

my old heads are cracked.
The guy told me it was an 87 HO GT longblock so I am assuming all the internals are for an HO GT. If the pistons, cam, and the rest of the internals were for an 87, would they work on these 86 heads?

Could someone with these 86 heads tell me what your numbers read on the top corners of the heads and if your valve covers are off the numbers in the top of the heads too?
Thanks

 

[SVT32VDOHC]

If the heads have a deeper thread count, than they are not stock Mustang heads. I had a set of aluminum heads on a 5.0L once, brand unknown, but I bought plugs for what type of car it was and they were the short threads. I ordered them for a Cobra 5.0L motor, and I got the deeper threaded ones. You will have to order them for a Cobra.

 

[1FatPony]

If the heads have a deeper thread count, than they are not stock Mustang heads. I had a set of aluminum heads on a 5.0L once, brand unknown, but I bought plugs for what type of car it was and they were the short threads. I ordered them for a Cobra 5.0L motor, and I got the deeper threaded ones. You will have to order them for a Cobra.

dont the 86 heads have deeper threads too?

 

[blkcobra50]

I have a pair of E6SE heads at home. I'm curious on the threading for the spark plug now. They don't flow as much as E7TE. I believe they were only on 86 mustangs.

 

[1FatPony]

Dont the 86s have some a swirl chambers from the deep plugs wo wouldnt that help the flow?