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LS3 vs. L92 heads...whats the difference?

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Old 11-27-2011, 09:52 AM
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Default LS3 vs. L92 heads...whats the difference?

I know the ls3 has hollow intake valves, but what are the other differences. I see a bunch of people using L92's but not many ls3
Old 11-27-2011, 10:04 AM
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LS3s have hollow intake valves, and the newer ones have better valve springs with a little more seat/open pressure (the blue springs). The rest of the port/casting is the same.
Old 11-27-2011, 01:40 PM
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Go with the LS3 the hollow valves are really a good thing to have if you are running any type of cam.

Tim
Old 11-27-2011, 10:05 PM
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The hollow stem valves are weaker than the solid valves. Big cams and heavy springs are hard on them. My head porter recommended L92's. Just sayin.
Old 11-27-2011, 10:08 PM
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I dont know why he told you that. When I read of people talking of valvetrain lighter is always better. It allows for better valve control and stability.
Old 11-28-2011, 12:26 AM
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For 99.9% of builds is it going to matter either way?
Old 11-28-2011, 12:45 AM
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stronger is better in valvetrain.parts are small, so light weight really means nothing except in rotating assembly.
Old 11-28-2011, 02:19 AM
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Originally Posted by Leeroyws6
stronger is better in valvetrain.parts are small, so light weight really means nothing except in rotating assembly.
Your advice giving card has just been revoked.
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Old 11-28-2011, 06:16 AM
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Wow this sounds like a mustang site with the newest 18 year old giving sound engine design advice.

Guess you need to call and start consulting for NHRA prostock. They have it all wrong.

Google is your friend not what your buddies uncle that worked in NASCAR told you.

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Old 11-28-2011, 06:28 AM
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Originally Posted by DietCoke
Your advice giving card has just been revoked.
ROFL.
Old 11-28-2011, 07:14 AM
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The trend for making power over the broadest rpm range is to have the lightest, stiffest, strongest valvetrain you can. The lightest valves & rockers, the stiffest pushrods, the strongest springs. You need valve control along with fast opening and closing of the valves. Always go for the lightest valves you can afford that will last. Weight is the enemy and trust me, those stock L92 valves are HEAVY.
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Old 11-28-2011, 07:15 AM
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For real! Some people have no idea wtf they are talking about so they just regergitate random bits of false info.
Old 11-28-2011, 07:37 AM
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So I take it the LS3 head would be the better choice of the 2? Trying to decide between the PRC stage 2.5 5.3 heads and the PRC ported l92's which I could order with the lighter valves for my LQ4 build.

Car is 3100# carb, th350, 8" converter and 4.10 gears.
Old 11-28-2011, 08:13 AM
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The ls3 heads certainly flow better. You may want to consider milling them .020 - .030 for better compression ratio
Old 11-28-2011, 08:32 AM
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Originally Posted by Tainted
The ls3 heads certainly flow better. You may want to consider milling them .020 - .030 for better compression ratio
Over the 5.3's yes. However, l92/ls3 heads might be too much for a smaller CI motor with a pumpgas friendly setup, out of the box they are 260cc intake runners. I personally wouldnt reccommend them (ported version) for anything less than 400 cubic inches.
Old 11-28-2011, 10:54 AM
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Yeah I was gonna say unless you are building a stroker of some sort then you dont need them ported. I have a set of LS3 heads in the floor here and ordered another set last night due to a little issue. 821 or 832 heads are the same casting (like 243's and 799's), just depends on what the head went on as to what valve it got, least thats my understanding. There have been reports of Camaros having 823 casting heads but Im sure they have the hollow intake valve. Lighter is BETTER.
Old 11-28-2011, 09:44 PM
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Originally Posted by DietCoke
Your advice giving card has just been revoked.
Lmfao!!

There seems to be a migration of these guys from somewhere that have NO CLUE! I wonder where they are from?

Diet you kill me!
Old 11-30-2011, 12:34 PM
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well I went LS3...got my fingers crossed.
Old 11-30-2011, 12:41 PM
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Originally Posted by streetknight2
well I went LS3...got my fingers crossed.
clearly the better of the choices. good luck!
Old 11-30-2011, 12:59 PM
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Originally Posted by Tainted
clearly the better of the choices. good luck!
Now gotta figure out cam. I called comp and they spec'd a monster lol.

255/267 --------624/624------108

What do you guys think. It will be carb with vic jr, 3100# car, 4.10 gears 8 " converter, etc.


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