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Discussion Starter · #1 ·
Hi,

Time has come to buy new heads for my 92 RMW L05.

I have decided to go for GM perf parts and 2 options exist.

Service replacement heads 93438649 (300 USD each)

Or Vortec heads 12558060 (400 USD each) but need Vortec intake maniflod for TBI # 12496821
The new manifold may not be adapted to the Ignition distributor whic is (as I understood) more compact on the Caprice/roadmaster). What abour EGR then ?? I do not know how to keep it with those heads

Cost wise and to keep it simple I would prefer to go for the service replacements heads but I am not even sure if those will fit OK without adaptation or anything ...

If Vortec fits Ok too and offer significant improvement then why not but I am not sure of installation process.

Anyone did it already ?
 

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You would be far better off with NEW Edelbrock Heads for near the same price.

or completely reconditioning what you have.
 

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or go to junkyard and find set of vortec heads and intake and have them redone. thats what i did with my 89 caprice 9c1 with the L05 in it. i think everything to get done was about 500 and that was price of heads and intake, getting them cleaned and reconditioned. there are hundreds of combos available for that car because its a gen I block. you could probably do a complete top end on that car to include cam for about 1000-1200 and have a very fun car. i think i had about 2500 in my caprice and that included topend, tranny, and tq converter. it already had 3.42 and a posi. that car was a fun bastard.
 

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Discussion Starter · #4 ·
keep in mind I am on the old continent :D

Junk yards here are only full of european cars. No way I can find a V8 except BMW or Mercedes ...

And I doubt shops around will do any good job on GM heads. Even if they are qualified, they will be either in Paris (700 km from me) and finally it will cost same price as getting new heads.

I want to pay for the best - perfect fit - heads for my L05 (I have an ECM with EBL flasher installed).

Then I plan to install headers and dual system.
 

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I want to pay for the best - perfect fit - heads for my L05.
Then shy away from the Vortecs. They have intake manifold distributor and EGR issues to deal with.
Better off with a set of stock replacements or GMPP fast burn heads. But if you don't change the weenie LO5 camshaft then you are wasting a set of performance heads, IMO.
 

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Discussion Starter · #6 ·
Well I do not want HO engine but would like to improve efficiency of the engine. If heads and exhaust manifolds are just crap on the L05 I can only take benefit of improved ones ! I even plan to get better MPG.

We have emission test every 2 years but it is only at idle (CO2 %) so I doubt the EGR will be needed in the new setup as it opens only in cruise. And with EBL flasher I can set it without EGR easily. Problem is that no EGR means higher T°C in the engine and possible spark knock.

Main problem will be the Ignitor I fear. I have no idea what I can do to fit the OEM one on a vortec intake manifold ...
 

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Discussion Starter · #7 ·

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Discussion Starter · #8 ·
found that CH350G is a bare head.

I prefer to get a fully equipped head that fits straight onto the Caprice L05 with stock intake and EGR !

Edelbrock Performer seems to be OK but it is 670 USD each :(

GM performance stock Iron cast head turn into lower Compression Ratio so I have to stick to the 64cc ...

No one ever did that before on a L05 Caprice or Roadmaster ???? cwm3
 

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Discussion Starter · #9 ·
My L05 is a 350 - 5.7L - 4" bore - I have never seen any Roadmaster with the L03 305ci - which is good !!!! :)

I found SUMMIT HEADS SUM-162108 ALUMINIUM. 1000 USD for a PAIR :D

BUT combustion chamber is a bit smaller (62 Vs 64 OEM) I hope this is not an issue ? COMPRESSION RATIO IS 9.8:1 so it will get closer to 10:1 afetr that !!! hopefully I use only high octane fuel (RON 98)
 

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Bump!

Is it possible to replace stock 96 LT1 heads with Vortec 5.7 / 350 heads? I don't know if this is a dumb question or not because I'm new to this..
 

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You can, but you have to drill the steam vent holes on the SBC heads because of the reverse cooling on the LT1. Some of the folks have noted that the coolant holes don't always line up, either, but there are several different styles of coolant passage so your best bet is to lay an LT1 gasket on the head you're interested in and make sure everything lines up.
 
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