Aluminum or Iron heads???

[zog]

I have an 86 coupe and don't know whether I have the cast iron heads or the aluminum ones, and have no idea how to tell the difference. I would like to put new plugs in it, but there is a difference...help and uninformed individual...thnaks

 

[92ghost]

I'm pretty sure that Aluminum heads have the bolts going through the center of the valve covers. Iron heads have the traditional 2 on top and 2 on bottom bolt pattern on the valve covers. I want someone else to chime in and verify this to be sure...

 

[Edmond]

I think that aluminum heads made their debut in 87' or 88'. I'm pretty sure it's one of those years.

 

[Edmond]

You do have aluminum heads! This is confirmed via:

http://corvetteactioncenter.com/specs/1986/86specs.html

 

[zog]

They aluminum heads came out in the middle of 86....so, some have iron heads and some have aluminum...I just don't know which I have....I checked with a Chevy dealer and they verified the years but did not know the difference. I don't think I'll have any work done there

 

[Vettelt193]

Not sure on the technical explaination, but you can usually tell by opening the oil fill cap and looking in with a flashlight. If you look straight down and it is a fairly bright silver, you have aluminum.

The other option is to just take a spark plug out and check the label. If you know what plug you have now, you can match to it, and figure out aluminum Vs. cast iron that way.

The final way is to do it by your VIN number.

 

[sumoboy]

Take a magnet and if it sticks it's cast iron

 

[boblx2a]

My '86 also has the iron heads. I was buying some parts at a parts store and asked the guy if I had iron or aluminum. He walked out and looked at it and said it was iron heads. He scratched a spot on the side of the head and said the it was not aluminum so it must be iron. Good thinking!

..........

 

[Moonunit 451]

sumoboy nailed it . I have an early 86 and I have cast iron heads as well

 

[Codeglia]

Iron vs. Aluminum heads

This is an easy one... Cast iron heads were used up to mid-'86 L-98 vehicles...then aluminum heads were introduced (still in the 1986 year). The easy way to tell is if the valve covers have their mounting bolts in the center of the valve covers, they are definately the aluminum heads. If the covers have their mounting bolts on the outer edges of the valve covers (two on top, two on the bottom), then it is definately the cast-iron heads.

Hope this helps!

Bob

 

[offshore]

They aluminum heads came out in the middle of 86....so, some have iron heads and some have aluminum...I just don't know which I have....I checked with a Chevy dealer and they verified the years but did not know the difference. I don't think I'll have any work done there

thats what I thought because if I HAD TO BET i'D HAVE GONE CAST.

 

[Moonunit 451]

OK, so which is better

 

[offshore]

OK, so which is better

not the cast ones!

 

[SlowRide]

For what its worth:

1986 Corvette

Suffix:
DKF: 350ci,230hp, ih (iron head), at (automatic), oc (engine oil cooler)
DKC: 350ci,230hp, ih, at
DKH: 350ci, 230hp,ih, at, ex (export)
DKD: 350ci, 230hp, ih, mt (manual tranny), oc
DKB: 350ci, 230hp, ih, mt


ZJS: 350ci, 235hp, ah (aluminum heads), at, oc
ZJH: 350ci, 235hp, ah, at
ZKD: 350ci, 235hp, ah, at, ex
ZJW: 350ci, 235hp, ah, mt, oc
ZKA: 350ci, 235hp, ah, mt

Block: 14088548: All

Head: 462624: iron heads/14101128: aluminum heads

*Notice the 5 hp increase with the aluminum heads.


Nick

 

[Moonunit 451]

Thanks:duh

 

[Edmond]

OK, so which is better

Definitely the aluminum ones. They disapate heat much better than iron and if you want to port and polish the heads some where down the road, aluminum is much easier to work with.

 

[muddywaters]

Heads

Edmond, Porting? Lay gasket in place on head , mark, and remove any metal that extends into port , neatly. Did it on my 79 L-48, made a difference. Am I correct on that Edmond ? Thanks

 

[Edmond]

Re: Heads

Edmond, Porting? Lay gasket in place on head , mark, and remove any metal that extends into port , neatly. Did it on my 79 L-48, made a difference. Am I correct on that Edmond ? Thanks

Yep, tha'ts correct. I will get that done someday... I sometimes wonder why they don't come from the factory like that.

 

[muddywaters]

Heads

The cost, I suspect. Thanks

 

[Bob Yates]

This is just a tip. Make sure you remove your Spark plugs with the engine cold if your heads are aulminum. Removing the plugs from a hot aulminum head could strip the plug hole. I have a 86 C4 conv. with aulminum heads....Bob