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Jul 1, 2007 | 01:17 PM

williammackean

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St. Jude Donor '07

Heads Question

The valve seals on my 85 4+3 (72k) are leaking. I am replacing the exhaust with headers on back soon. I also have a set of '86 aluminum heads in my basement. I am having the plenum ported, too.

Question:
Would it be significantly more expensive to change the heads? or should I just have the valve seals replaced?

I am not capable of doing this myself. I figure that the exhaust is already detatched, the plenum is off... Now would be the least expensive time to change the heads, otherwise I'm selling the aluminum heads.

Lastly: I have the '86 valve covers, too.

Jul 1, 2007 | 02:02 PM

tjwong

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From: Portland Oregon

Quote:

Originally Posted by williammackean

If you have the intake off, and the headers off. You are an hour away from removing the heads. All you need is a set of head gaskets and if you wanted to splurge a set of new head bolts.

Jul 1, 2007 | 03:11 PM

aboatguy

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From: Slidell Louisiana

Quote:

Originally Posted by tjwong

If you have the intake off, and the headers off. You are an hour away from removing the heads. All you need is a set of head gaskets and if you wanted to splurge a set of new head bolts.

Install your aluminum heads.

Jul 1, 2007 | 06:10 PM

BADDUCK

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From: One day you're a Comet...the next day you're dust... Arkansas

Have them ported first then put on aluminum and replace the rockers with full rollers.

Jul 1, 2007 | 06:38 PM

williammackean

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St. Jude Donor '07

Quote:

Originally Posted by tjwong

If you have the intake off, and the headers off. You are an hour away from removing the heads. All you need is a set of head gaskets and if you wanted to splurge a set of new head bolts.

I am not sure if the intake needs to come off or not. The plenum will be off, and maybe the fuel rail if I swap the injectors. Still, the extra time will prolly be worth it.

Quote:

Originally Posted by BADDUCK

Have them ported first then put on aluminum and replace the rockers with full rollers.

I'll ask my guy if he thinks porting is worth the $$. I think it would be, but he is famous for telling me not to bother with some things.

He'll also be replacing the oil pan gasket & seals. Prolly hit the knock sensor & connector while we're there. They got coated pretty well when the vc gasket went last year.

Aluminum chamber vs iron chamber: 64cc vs 176? Am I right?

How much would full roller rockers run me?

Thanks!

Jul 1, 2007 | 07:10 PM

CFI-EFI

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From: The Top of Utah

Iron heads, 76 cc combustion chambers. 128 or 113 aluminum heads, 58 cc combustion chambers. That will give you something over 11:1 compression ratio, with no other changes. If you plan to use the EGR, don't forget the EGR tube and the '86 intake manifold base. The aluminum heads don't have the exhaust passages for the EGR gases.

RACE ON!!!

Jul 1, 2007 | 07:21 PM

Corvette Kid

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St. Jude Donor '04-'05-'06-'07

Quote:

Originally Posted by williammackean

I am not sure if the intake needs to come off or not.

Jul 2, 2007 | 01:49 AM

williammackean

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St. Jude Donor '07

Quote:

Originally Posted by Corvette Kid

Meaning that one can replace the seals with the heads attached, so I'm not sure it's worth the $$ for removing the intake and such.

Oh, and I do have an '86 intake, too. I'll hafta search for the bennies of keeping/ditching the EGR. Anyone care to point a guy in the right direction?