View Full Version : Heads?


chevySS08
05-27-2010, 07:31 AM
so ive been reading of some of the gxp guys getting heads for there ls4's. my question is are they buying factory heads and porting them theirselves or is there an actual performance head out there? from what chevy has said the ls6 head will not fit the 5.3 ls4 so ya im gettin a little irritated with that, haha, any info will help. thanks

williamGT
05-27-2010, 08:38 AM
The 5.3 LS4 has the LS6 heads.

94ss06gxp
05-27-2010, 09:14 AM
The 5.3 LS4 has the LS6 heads.

yup :cheers:

indynotch50
05-27-2010, 09:52 AM
See sittingmongoose's statement a few posts down...

http://www.ls1tech.com/forums/ls4-front-drives-2005-2010/1285665-answer-questions-about-stroking-boring.html

chevySS08
05-27-2010, 12:40 PM
so basically the guy at chevy is an idiot then? wow

AlabamaGuy
05-27-2010, 12:44 PM
I believe we have smaller valves but the castings are the same. 243s

chevySS08
05-27-2010, 05:03 PM
k last question, i need an opinion im going to do a custom exhaust, 2 1/2 inch piping, which do you alls think sounds better the magnaflow mufflers or the flowmaster 40 series? i like both, hate my indesiciveness

AlabamaGuy
05-27-2010, 05:06 PM
k last question, i need an opinion im going to do a custom exhaust, 2 1/2 inch piping, which do you alls think sounds better the magnaflow mufflers or the flowmaster 40 series? i like both, hate my indesiciveness

Don't buy a Flowmaster. Anything but a Flowmaster.

But why limit yourself to those 2 mufflers? There are a ton of choices in the aftermarket.

JDMC5
05-27-2010, 07:28 PM
same style heads but smaller intake valve. The bigger intake valve will work but I haven't seen any data that supports a hindrance or gain in power. Yes, you do get the benefit of the bigger valve but the small bore increases shrouding sooooooo. But anyways, stock ported heads will flow pretty damn good, if you're adding a cam get them milled and up the compression.

AlabamaGuy
05-27-2010, 08:32 PM
same style heads but smaller intake valve. The bigger intake valve will work but I haven't seen any data that supports a hindrance or gain in power. Yes, you do get the benefit of the bigger valve but the small bore increases shrouding sooooooo. But anyways, stock ported heads will flow pretty damn good, if you're adding a cam get them milled and up the compression.

Thanks for backing me up on this, JDM. There is absolutely no point in putting aftermarket heads on these motors without some kind of crazy setup. Our cam and intake don't allow full use of the stockers as it is, and to be honest, we don't have any header choices that will accompany good, high RPM power (ie LTs). Bump compression and let her ride.

indynotch50
05-27-2010, 09:11 PM
Don't buy a Flowmaster. Anything but a Flowmaster.

But why limit yourself to those 2 mufflers? There are a ton of choices in the aftermarket.

Man why hate on the flowmasters? Those were the hot ticket for years. Ha. I tend to like them.
Anywho. He's right. The bad part is they don't make kits for these cars. The good part is that they don't kits and you get to explore different routes. A lot of guys use spintechs.

AlabamaGuy
05-27-2010, 09:40 PM
A lot of guys use spintechs.

Never looked back either.

JDMC5
05-28-2010, 01:22 AM
No problem. Don't quote me on that though, haha.

FWIW, I have a magazine where they put larger valve heads on a 5.3 with a big cam, fast intake and long tubes, the made 458hp..........