Ls1 heads

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Dec 31, 2015 | 03:40 PM

Mbcky2

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Ls1 heads

I have a 5.7 with ls6 intake and 241 heads. I want to upgrade the cam and I'm wondering should I also do the heads and well to 799 or 317. If anyone has any comments or have done something like this I would love to get some info.

Dec 31, 2015 | 03:46 PM

Jtm2085

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I would go to the trouble to swap a stock ported head on the car. Get some 799's or 243's and have them ported

Dec 31, 2015 | 03:56 PM

HCI2000SS

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From: Howell & Fenton MI

Have a certain budget or goal here?

Dec 31, 2015 | 04:45 PM

Mbcky2

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Quote:

Originally Posted by HCI2000SS

Have a certain budget or goal here?

I'm just trying to get the best for my money. Don't really have a budget.

Dec 31, 2015 | 05:11 PM

HCI2000SS

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From: Howell & Fenton MI

Do you have a cam in mind? What other mods do you have, what gear and trans?

Dec 31, 2015 | 05:48 PM

Mbcky2

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Quote:

Originally Posted by HCI2000SS

Do you have a cam in mind? What other mods do you have, what gear and trans?

I don't have a cam in mind just yet I was going to look and the heads an go from there. No other mods beside I have a ls6 intake. 3.73 gears and I'm going with a 4l65e the motor came out foam 01 Pontiac firehawk.

Jan 1, 2016 | 12:14 PM

vettenuts

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From: Little Rhody

If you can afford the down time, AI has a good porting program for the 241's.

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Jan 1, 2016 | 07:36 PM

Black02SLP

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If you go with 317 heads it will drop your compression. The 317 heads have a 70cc chamber. That's the boat I'm in now. Your 241 heads have a 200cc intake runner and the 243/317 has a 210cc intake runner. The 243/241 heads have a 64cc chamber I believe.

Jan 1, 2016 | 09:59 PM

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Mbcky2

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Quote:

Originally Posted by Black02SLP

Ya I don't want to drop the compression. What's the compression ratio on the 317?

Jan 1, 2016 | 10:33 PM

#11

SlasherVRGR

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From: NEPA

Quote:

Originally Posted by Black02SLP

243 heads have a smaller combustion chamber than 241s I'm pretty sure..

Jan 2, 2016 | 02:54 AM

#12

Black02SLP

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Casting Number 241
Head: 1997+ LS1 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12559853 (1997-98)
12559853 (1999-00) (not sure why same PN)
12564241 (2001-03)
Combustion Chamber Volume: 66.67cc
Compression Ratio: 10.1:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 243
Head: 2001 LS6 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12564243
Combustion Chamber Volume: 64.45cc
Compression Ratio: 10.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 317, 035
Head: 2001+ LQ4 and LQ9 6.0 Liter Truck
Material: Aluminimum
Part Number:
12562317 -LQ4
12572317 -LQ9
12572035 -LQ9
Combustion Chamber Volume: 71.06cc
Compression Ratio: 10:1 LQ9 Flat top pistons
Compression Ratio: 9.6:1 LQ4 Dish piston
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Got this off another site.

Jan 2, 2016 | 02:56 AM

#13

Black02SLP

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Quote:

Originally Posted by SlasherVRGR

243 heads have a smaller combustion chamber than 241s I'm pretty sure..

You'r right. Sorry for the bad info.

Jan 2, 2016 | 07:37 PM

#14

Mbcky2

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Quote:

Originally Posted by Black02SLP

Awesome thanks for the chart.

I wonder how hard it would be to find a set of the 317 heads at the junk yard or online.

Last edited by Mbcky2; Jan 2, 2016 at 07:47 PM.

Jan 2, 2016 | 08:10 PM

#15

ragtopz28

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From: Ft. Myers, FL

Quote:

Originally Posted by Mbcky2

Awesome thanks for the chart.

I wonder how hard it would be to find a set of the 317 heads at the junk yard or online.

Not hard at all...I've sold 2 sets recently for $150-175. Have you looked in the classifieds here or your local CL?

Jan 2, 2016 | 08:14 PM

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redtan

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Quote:

Ya I don't want to drop the compression. What's the compression ratio on the 317?

You can always mill the 317s to match the old heads in compression.

Personally I'd either do the high compression welded 317s from AI. You get the best of everything...better flowing than 241 heads, more compression and no changes in PTV even with a small chamber...all that doesn't cost anymore money.

Feb 2, 2016 | 09:59 PM

#17

Mbcky2

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I email That company about CNC my heads I have and I'm looking at a 1000 bucks for that. He recommended I get a set of 243 heads which I would still have to buy, and send those in. Plus 300 for the new springs. Is it worth it to go that way or buy a new set of ls3 heads already ported from jegs. I'm still just trying to figure out what would be best. Or any more info.

http://www.jegs.com/i/Chevrolet-Perf...8758K/10002/-1

Feb 2, 2016 | 10:25 PM

#18

A.R. Shale Targa

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From: Fredonia,WI

LS3 heads have 2.165" intake valves which will not clear your 3.898" bore
Stock 243/799 heads milled .030" with a fresh valve job and BTR dual springs
Would be your best budget bang
Toss in a stage one BTR cam or a Cam Motion Titan IV with some decent headers
And you'll have a strong combo

Feb 2, 2016 | 10:32 PM

#19

Mbcky2

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Quote:

Originally Posted by A.R. Shale Targa

Ya I just looked into that. I think I will end up just doing the cam a changing the springs on mine. Unless I can find a decent set of head. What would be good with that cam? The 243? Or just run it on the 241s I have

Feb 2, 2016 | 10:44 PM

#20

kinglt-1

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From: Ft. Wayne, IN

I would have AI do the HC 219cc package on your 241's...u less you come across a good deal on a set of worked 243's. Somebody was so gracious to offer me a set last year at a fair price ...wink wink.