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Discussion Starter · #1 ·
Ok, so I've been searching around regarding aluminum heads. I picked up a set of #12551561 heads supposedly from a late 90's Camaro.

I read on here that just going aluminum hurts performance as the irons flow more. I mainly bought these because I might have an exhaust manifold bolt on my 9C1 irons that likely isn't going to come out.

Should I get these babies ported before I put them on to get at least equal performance? Who is the best porter?? or can most engine/machine shops do it? Other than that I guess I should throw on some new springs...any other suggestions?

I'm not looking to go crazy fast...not going to race...just want to get all the header bolts in the heads and not lose a lot of HP in the process. :)

Thanks!
 

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LLoyd Elliot or advanced induction are two of the best and most used on this forum
 

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If you're staying with the stock cam, then porting them will do you little to no good.
I'd use them as is, with the stock Impala .029" or MrGasket/Felpro .026" head gasket.
You may even notice a performance increase with the 3/4 point extra compression. I assume you're running the stock program.. ?
 

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If you're staying with the stock cam, then porting them will do you little to no good.
I'd use them as is, with the stock Impala .029" or MrGasket/Felpro .026" head gasket.
You may even notice a performance increase with the 3/4 point extra compression. I assume you're running the stock program.. ?

I concur..!!

IMHO
If you are going through the painful process of removing the top half of the engine (especially if you have never done one)
add
a performance cam with the Ported Heads.

The performance increase will be dramatic.

Also before any major engine modification.
Take the car to a car wash
and
Wash, steam, scrub clean the engine and compartment.
Including the radiator and AC, wheel wells, suspension.

It will be a lot more fun.

Dan
 

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if it is the rear exhaust manifold bolt that is broken and you are installing headers....the headers use the inner holes so a broken bolt on outer hole is no problem.\

fwiw, most agree stock iron heads flow better than stock AL heads
 

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you got the wrong heads for porting "Core must be casting number 10207643 or 10128374 "
http://www.advancedinduction.com/AiProductsLT1.html

Does not really matter.
You can port and polish them and will come close.
Otherwise you have to find a set.

FWIW
Ported Irons can be ported even larger than any of the LT1 Aluminum heads.
and
you can add larger valves for even better flow.


D
 

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Discussion Starter · #8 ·
Thanks for the help guys!

I'll see where this manifold bolt problem takes me. I've got one on each side that isn't a non-used header bolt.

If I can't get 'em out I might turn this head replacement job into a performance geared upgrade, port/polish, cam, throw on an opti/waterpump, etc.

I'm always up for a good "can of worms" project :)
 

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