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Absolute Best LSX Head?

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Old Dec 9, 2005 | 11:17 AM
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Default Absolute Best LSX Head?

I'm about to upgrade the heads on my C5R 427, and would appreciate input as to the best flowing head currently available for my engine. I want to avoid sheet metal intakes, so the C5R head is out. I'm running a moderate cam (236/242/112 LSA/.604"), and the car is primarily street driven with a couple of road course track days a year. Since the engine was built in late 2002, I've run ported LS6 heads which don't flow all that well, showing only 292 intake and around 215 exhaust at .600" lift.
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Old Dec 9, 2005 | 11:20 AM
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I am hearing good things about ETP's new LS7 style head... this combined with GM's LS7 intake and your displacement should result in some impressive numbers...

It would good to hear from someone from ETP to get thier perspective...
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Old Dec 9, 2005 | 11:27 AM
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V max hit it on the head.
You are lucky to have the 427 already.
You get the 4.125 bore which is what the LS7 head was designed around.
If using the LS7 head or LS7 style head you can also use the LS7 intake.
ET performance is making the best head right now for our market.
If you didn't want to swap intakes you could run their LSx style 245cc head and have some very impressive results.
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Old Dec 9, 2005 | 11:27 AM
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Old Dec 9, 2005 | 11:46 AM
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If your running a 346 to 408cid motor I would go with the ET Performance 11 degree LSx style heads. Their flow numbers are better across the board hands down. For a 420-500cid LSx, I would wait until their splayed valve head is done. The new head flows in the low 400cfm range over the top of the lift and coupled with a sheet metal intake manifold should make crazy power.
Phil
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Old Dec 9, 2005 | 11:50 AM
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A BIG ET head
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Old Dec 9, 2005 | 03:33 PM
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my next heads will be ETP so another vote for that
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Old Dec 9, 2005 | 03:38 PM
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Has anyone heard anything about ETP's upcoming LS7 style heads?
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Old Dec 9, 2005 | 03:46 PM
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On the SDPC website, they're claiming 370 cfm intake flow for their CNC'd LS7 heads. Wouldn't these be another contender?
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Old Dec 9, 2005 | 05:22 PM
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The splayed valve heads are going to be a race only thing. The ports on those things were like 285cc's. Way to big for a mild cammed 427. Your best bet is going to be to contact ETP. They have many heads that will suit your needs. For your cam size, I'd reccomend the 240's, or 255's if you plan to stick with a LS-6 or FAST intake. You could also try the LS-7's or the C5-R's if you wanted to swap to a LS-7 intake. Their C5-R's have a LS-7 intake bolt pattern if you want.
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