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View Poll Results: Which heads would net me more power?
Stock 5.3L 862 Heads (Lightly ported)
8
53.33%
LS1 Heads (Lightly ported)
7
46.67%
Voters: 15. You may not vote on this poll

Which heads would net me more power?

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Old Dec 13, 2009 | 05:22 PM
  #1  
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Default Which heads would net me more power?

Hey guys, I'm in need of some help here. I'm trying to decide which heads would be better for my application. I've got a 5.3L LM7 engine (stock 862 heads) and I'll be upgrading to flat-top pistons for a bump in compression.

I'm trying to decide whether I should upgrade to the LS1 heads for their bigger intake valves or keep my 862 heads for their smaller chambers and higher compression ratio.

Both heads would be lighty ported...so what do you think?

Stock 862 Heads: 61.15 cc
Valve Diameter Intake 1.89"
Valve Diameter Exhaust 1.55"

LS1 Heads: 66.67 cc
Valve Diameter Intake 2.00"
Valve Diameter Exhaust 1.55"

Assume I would be using a TR224 cam (224/224 .563/.563)

Thanks for your help!


P.S. I know something like the 5.3L Stage 2.5 heads would be best for me, but I'm not looking to spend that much money.
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Old Dec 13, 2009 | 06:01 PM
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The ls1 heads have bigger intake valves they will flow better then the 862s. Just mill the ls1 heads down to get the compression up.
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Old Dec 13, 2009 | 07:22 PM
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x2...
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Old Dec 13, 2009 | 07:42 PM
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Hmm... 2/2 so far. Are you guys not worried about the loss of compression?
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Old Dec 13, 2009 | 07:55 PM
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Originally Posted by BrownBoy
Hmm... 2/2 so far. Are you guys not worried about the loss of compression?
You can regain any loss of compression by milling the heads.
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Old Dec 13, 2009 | 08:41 PM
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x2 again
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Old Dec 13, 2009 | 08:41 PM
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also you can use a thinner mls headgasket...
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Old Dec 13, 2009 | 08:43 PM
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x3, sounds like you get the best of both worlds and will have a higher top end at little to no cost on the bottom end.
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Old Dec 14, 2009 | 02:49 PM
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*bump*

Any more input? Only 3 votes in a day?
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Old Dec 14, 2009 | 02:56 PM
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Originally Posted by BrownBoy
*bump*

Any more input? Only 3 votes in a day?
Neither heads are my favorite if your going to purchase do 243s.

Now if your intent in doing 241 what you can do to help out your 241s would be get the LS6 valves. Have Advance Induction do the work to them they very good at what they do or Lloyd Elliot he is a genius with 241 heads. Keep the stock rockers and if your going after market go with Yella Terra.

My personal experience though you are wasting your time with 241 heads.
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Old Dec 14, 2009 | 03:13 PM
  #11  
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Originally Posted by 02*C5
Now if your intent in doing 241 what you can do to help out your 241s would be get the LS6 valves. Have Advance Induction do the work to them they very good at what they do or Lloyd Elliot he is a genius with 241 heads. Keep the stock rockers and if your going after market go with Yella Terra.

My personal experience though you are wasting your time with 241 heads.
Thanks for your input!
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Old Dec 15, 2009 | 10:05 AM
  #12  
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Looks like the vote has evened itself out...

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