I've seen them mentioned on here,I know people install them....what the hell are they and what do they do for you??

 

Aluminum cylinder heads. They are emissions legal and run about $2300to $2,400 a pair plus intallation. 300 cfm at .600 lift. 2.020 intake and 1.600 exhaust valves. 66cc combustion chambers. A good addition to your vette if you are seeking a mod package.

 

SO,I Would need how many at 2300-2400 a pair??What else needs to be done and what HP GAINS??THANKS.

 

I would go larger than the 205's for the LS2 (but thats just my opinion).
No question the AFR 205's are #1 for the LS1/6 but with our extra cubes better heads can be found. To really make them perfrom on an LS2 would require a porter to modify/reshape the chambers to take advantage of the larger 4” bore. The 205's will still give you good power, but the rest of the head community has caught up.
I would guess the AFR's would give you about 20HP.
I got about 25 with them on my LS6.
They are about $2,200 a pair. You would also need head gaskets, head bolts and coolant. About $200 more. Plan on $400-$600 to have them installed and about $500 for a tune.

 

Everything CYA-Vette stated is right on.

Some other considerations...
1. You only need one pair (ref: http://www.airflowresearch.com/205_mongoose.php). These are the pieces that hold your intake/exhaust valves, and sit atop the pistons.
2. The main function of aftermarket cylinder heads is to raise or lower compression ratio (dependent upon chamber size), and to optimize air flow volume/velocity.
3. Heads, like most other mods on LSx motors, are complimentary to other mods (i.e., greater than the sum of their individual gains). Heads set the stage for other mods to achieve their full performance, but by themselves, are not a very cost-effective upgrade (IMO). For example, if you replace heads, intake and manifold, you will have removed all restrictions to incoming air flow and achieve greater gains than might be expected by results gained from the individual pieces.

Even though I own a C5, I have an LS2-based 402ci stroker w/ ported AFR 205s and all the goodies. These heads work great with the motor in a stock C6. ETPs (if you can get them) and Edlebrocks are also worth considering.

The best advice I (or anyone) can give you is to evaluate your upgrade plans and discuss them with a professional (or someone who is knowledgeable, and who's opinion you trust). Otherwise, you may end up piecemealing non-complimentary parts together, or paying for the same labor multiple times.

 

So all i'd need is 1 pair.Thanks guys.

 

but also what do you want your car to do??

AFR 225s, a good cam, new timing chain, new oil pump ( LS2 stock one is a bit weak) and dyno tune your look at close if not 500 to the ground.

 

OK,I'm NOT doing a cam,don't like the lopy idle.I'm looking for ideas right now because at some point when the car is not so new anymore,i'll mod,like i've done to my last 2 vettes.I am considering a supercharger also.

 

The 225's have less than stellar TQ numbers in all the applications I have seen. The ETP 225's however would be an awesome head for the 364.

 

Your engine only has one pair of heads.

If you don't know the answer, chances are really good you don't need them.

 

Heads and no cam is pretty much pointless. The LS2 heads flow very well. You would probably only gain about 20hp with heads and no cam, get headers and a tune.

 

I've decided to try the PRC 2.5's. They should flow well over 300cfm at .600. I'll let you know the results when I get them on. They are almost free compared to AFR's and ETP's. Of course if they don't perform cost means nothing

 

I have the AFR 225 heads, 224/230 581/592 114LSA cam, Dynatech 1 7/8 headers and Corsa Sports with tune went from 350 rwhp to 443 rwhp and 399 rwtq. A by product is a fabulous sounding C6