Difference between 86 and 87 heads???

1FatPony

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Jun 5, 2005
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I bought an 87 long block and it suposedly came with 87 heads but I looked and they are 86 heads. Is there really that much of a difference? Will my 87 internals work well with these heads or do they have to be 86 specific internals. So should I just keep the 86 heads or get the 87 heads.
 
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86 heads don't flow as well as 87-95 heads. You can use them but they won't perform as well. Do not use 87-95 heads on an 86 block unless the 86 pistons are cut for valve relief.
 
well I bought an 87 longblock and it came with 86 heads. Is it worth the trouble to go back to the shop which is 300miles away and get the 87 heads or should I just stick with these 86 heads?
 
1FatPony said:
well I bought an 87 longblock and it came with 86 heads. Is it worth the trouble to go back to the shop which is 300miles away and get the 87 heads or should I just stick with these 86 heads?

Yes it's worth it!!!

And while your there ensure it has the proper cam and pistons.
 
Daggar said:
Are you sure that the heads you're looking at are E6TE heads? I can' timagine why someone woul dput them on an 87+ block.
that is a good point. Do you have a suggestion on what I should do? My ntake manifold is bolted dwn along with the heads. Is there any other way to determine if these really are 86 heads other than unbolting them?

Lets say someone did put on these 86 heads on an 87 block. Would they have to change the pistons, cam, etc?? I am just trying to etermine if it really is too much trouble for someone to actually convert to 86 heads.
 
No... they would not have to change the pistons on an 87 block. There'd be even MORE clearance on an 87 block than 86 because the 87+ pistons do not take advantage of the additional 1/4 of space between the piston face and the valve face.

Take the valve covers off and look for a number. Let us know what it is.
 
Ill check for numbers when I get home but do you know of any other heads that have these deeper threads? I know the GT40s do but dont they say "GT" on the side of the head? These dont say GT.
 
Just look for numbers on the heads... E6SE, E7SE, E7TE, ETC. I don't really know what else to tell you about physical differences you can pick out externally. Maybe someone else here might.
 
68stang351 said:
You can tell by trying to put a E7 head's spark plug in. The motorcraft 450 plug, if its E6 heads the plug won't go in.
I know they arnt E7 heads because the plug wont fit. Thats why Im trying to figure out what they are. If they are 86 heads then I will probably send them back but if they are aftermarket heads that are better than 87 heads then Ill just keep them
 
If they are cast iron heads then I doubt seriously that they're aftermarket. I can't remember ever seeing an aftermarket head for our cars that wasn't aluminum (not to say that some shlub didn't make a set).

If they're 86 heads though... yeah.. I'd send em back and get what you were supposed to get. Those things gotta be a dog over the top of an 87+ bottom end.
 
In the lifter valley (there may others as well). Getting a look at th etop of the pistons would be a good indicator as well if you decide to take the head(s) off.
 
Yeah man, just take a head off... you'll then you'll know what heads for sure and whether or not the bottom end is E7TE head friendly. I'll bet it's all 86 stuff, and I think you should really bring it back... plus have them reimburse you for expenses :)
 
I called the guy who I bought it from today and he wasnt very clear but it sounds like the 86s had valve shrouds on them for better emissions that was taken off in 87. These shrouds are what caused the poor air flow but also increased low end torque but it wasnt as good as the 87s at high rpms. It sounds like my internals are all 87 and its just my heads that are 86. It is also possible that the valve shrouds are not on which pretty much makes these 87 heads just with the deeper threads for the spark plugs which is actually benneficial. I dont think it will be worth the hassle to get the 87s. These heads might actually be better then them anyway.
 
1FatPony said:
I called the guy who I bought it from today and he wasnt very clear but it sounds like the 86s had valve shrouds on them for better emissions that was taken off in 87. These shrouds are what caused the poor air flow but also increased low end torque but it wasnt as good as the 87s at high rpms. It sounds like my internals are all 87 and its just my heads that are 86. It is also possible that the valve shrouds are not on which pretty much makes these 87 heads just with the deeper threads for the spark plugs which is actually benneficial. I dont think it will be worth the hassle to get the 87s. These heads might actually be better then them anyway.

Take the damn thing back! Seriously...you bought a 87 H.O. engine, not a 87 engine with 86 heads.

The vavle shrouds are not the only difference in design. I do believe the combustion chamber has a heart shaped design which severly limits high end air flow. There is a reason why no-one seeks out 86 heads for aftermarket use...and most with 86 stangs swap over to e7's.

Edit:

Here is a link with a lil bit of info... http://www.diyporting.com/E6TE.html
 
1FatPony said:
I called the guy who I bought it from today and he wasnt very clear but it sounds like the 86s had valve shrouds on them for better emissions that was taken off in 87. These shrouds are what caused the poor air flow but also increased low end torque but it wasnt as good as the 87s at high rpms. It sounds like my internals are all 87 and its just my heads that are 86. It is also possible that the valve shrouds are not on which pretty much makes these 87 heads just with the deeper threads for the spark plugs which is actually benneficial. I dont think it will be worth the hassle to get the 87s. These heads might actually be better then them anyway.

No amount of rationalizing is going to make those heads any better. lol

The only reason they performed as well as they did on the 86 is due to the higher static compression of the short block.