[blackax]

And from what I understand is that the LS3 Heads flow better then the LS7 heads on the low end but die out on the top

[blackax]

From wikipedia about the ls2

It is similar to the high-performance LS6, but with improved torque throughout the rpm range. The LS2 uses the "243" casting heads used on the LS6 (although without the sodium filled valves), a smaller camshaft, and an additional 18 cubic inches. The compression of the LS2 was also raised to 10.9:1 compared to the LS1s 10.25:1 and the LS6s 10.5:1

[C5Natie]

Originally Posted by blackax

And from what I understand is that the LS3 Heads flow better then the LS7 heads on the low end but die out on the top

Ls3 heads flow great up top with the right cam. If anything port velocity can suffer when the heads get ported too much, losing a bit of torque on the bottom end. It depends on cam selection but Ive seen LS3's make great power up to 6800rpm or higher. The intake ports and valves are so big that you dont need as much duration on the intake side and the right cam can maximize the exhaust velocity.

I think the 6.2L motors are fast becoming the best bang for the buck project motors. A brand new set of GMPP LS3 heads cost me $640 for the pair, new and complete. Also, so many trucks/suvs and cars have the 6.2L that theyre getting easier to find.

[C5Natie]

I think the C6 LS3 revs up to 6600 but the stock valve springs suck luckily they can get away with a smaller cam due to how good those big valves flow. Maybe thats why some may say they "die up top" vs an LS7, being stock that is.

[blackax]

Originally Posted by C5Natie

Ls3 heads flow great up top with the right cam. If anything port velocity can suffer when the heads get ported too much, losing a bit of torque on the bottom end. It depends on cam selection but Ive seen LS3's make great power up to 6800rpm or higher. The intake ports and valves are so big that you dont need as much duration on the intake side and the right cam can maximize the exhaust velocity.

I think the 6.2L motors are fast becoming the best bang for the buck project motors. A brand new set of GMPP LS3 heads cost me $640 for the pair, new and complete. Also, so many trucks/suvs and cars have the 6.2L that theyre getting easier to find.

I agree on the power the stock heads can make with the LS3 I was just comparing them to the LS7 head.

I'm a fan of all the gen IV small blocks (ls2,ls3,ls7) I love my LS2 and the truck blocks are so nice for huge boost numbers (cant beat iron blocks in huge Fi numbers)

[C5Natie]

Yeah, theyre very similar heads. LS7 intake valves are 2.20" vs the LS3 2.165" and theyre cc is for a 4.10" bore minimum so theyre gonna flow a bit more up top. Thats why they got crazy top end. But now even regular LS3 Vettes are hitting 180mph+ stock. Crazy. We are now in the golden age of performance, muscle cars cant touch this technology.

[C5Natie]

Heres a thread with a guy, screen name Burrhos, making 517rwhp/462rwtq with cam only bolt on LS3 C6, n/a. Ran 10.67@129mph. See post #8.

http://ls1tech.com/forums/generation...ed-please.html

[Ryridesmotox]

Originally Posted by Damian

Isn't the LS6 505hp stock compared to 420hp?

405hp in the z06. Other applications like the CTS-v and the GTO have other outputs I think. Just figured I would answer your question. And the sodium filled valves thing is actually pretty sweet. Apparently it allows the valves to remain cooler or something like that.

I agree with you Natie, this is the golden age of performance. You cant find a muslce car that will get over 400hp and still get almost 30mpg like a vette. The technology is amazing now. My cobalt motor internals can handle 500whp from the factory. The LS blocks are total beasts, and the OHV pushrod design is tried and true, and I don't think its reliability and power can really be questioned.

[C5Natie]

Well, I got a lot done this past weekend starting thursday. Got the motor in and assembled it. Turned it over to prime the oiling system and connected the converter box. Should start it up today and button up the car. I'll post some pics of what Ive been up to. Looking forward to getting video of start up, if it starts, and idle, if it stays idling. Lol

Thanks to my friends Carlos, Adrian and my uncle William for lending a hand this weekend. And NO-Xplode for giving me the energy.

[C5Natie]

Made the notch for the bracket to fit. Not pretty but it worked.