What is the real difference between LS2 GTO heads compared to stock LS6 heads? Do they net the same power gain? Same all around or what?

 

The valves are the only difference I know of.

LS6's have lighter weight sodium filled valves so they can sustain a little higher revs. Same casting number and flow characteristics.

 

PBMFisMe said it. If You are buying a set of 243's be sure to weigh the valves to determine if You have an LS6 head (light valve) or LS2 head (heavy valve). I know because I bought a set of LS6 heads on this forum and after I got them found out they were LS2 heads. Yeah I feel like I got ripped! Carl.

 

Does the valve weight really make that big of a difference? I do have an M6 GTO. I don't plan on revving it all that high though. Aren't LS1 heads equipped with the solid heavy valves?

 

In terms of reliability and endurance, yes. GM would't have encountered the additional expense if they felt there was no merrit to lighter and more expensive sodium filled valves on higher revving LS6's.

 

just the valves are differnt

 

the valves are different but not necessarily better. the hollow valves have had trouble with breaking. people have had them break and ruin motors. it has its advantages but has its disadvantages. if it was really so good then the after market head companies would do it also.

as far as the differences between gto and ls6 heads what they are saying is only partially true. the 01 z06's got the same setup on the heads as the gto heads. no sodium valves. they are all ls6/243 heads some just have different valves.

 

arn't the lighter sodium filled valves for rpms above 6500?? and stronger springs on the LS6 heads.

and if you dont have the lighter valves and strong springs there maybe some serious valve float above 6500 as well?

 

What about the factory LS2 springs off the GTO? What lift are they good up to? Will they handle a factory LS6 cam?

 

I'm pretty sure the LS2/LS6 springs are the same.

 

the 05 gto's came with the 01 z06 cam. the 05 gto springs will be fine with a ls6 cam. honestly if you are going to do a cam swap you should go bigger. some people like the ls6 cam but its alot of work for the minimal gain you will get. if you still want a smallish cam, go with a 224 range cam. you would need better than ls6 springs but comp 918's would fine and are pretty cheap.

 

Can the stock LS6 valves be used with an aftermarket cam? I thought the valves were a different length because the LS6 cam had a smaller base circle.

 

Valves no, Rods were longer for the Z06 cam.

The Z06 cam is a good cam, but if you are putting in a cam, go with something better then the Z06 cam



stock:
LS1 cam 198/208 500/500 116 LSA
LS2 cam 204/211 525/525 116 LSA
LS6 cam 207/217 525/525 116 LSA

Other GM cams for comparision
Hot cam 219/228 525/525 112
ASA cam 226/236 525/525 110
Cup Cam 239/251 570/570 106