difference in z06 valve spring colors...
 

Thanks for looking...

I am about to buy some z06 heads, they have the red dots on the valves, but the springs are a natural looking finish rather than the yellow I'm used to seeing.

They are still legit and will work with the newer Z06 cam right?

Thanks again

my 02 Z06 did not have yellow springs either... not quite sure why as i havent really looked into it but low and behold my valve springs also failed... not quite sure what that means for you but im guessing they are legit springs, whether or not they are the good ones i have no idea!

they are the ls2 heads i think. the orange dots are the sodium filled valves.

LS2 heads use cast # 243?

Thanks for the replies, anyone else with input?

Was told this in an email, how's it sound? :

"These are cast as 243 heads-the same as a Z06 head but without the
lightweight valves. Chevy used the lightweight valves from 02-04 then
stopped. These are the same as a 01 Z06 and the 05 and up C6's. These heads
are on the LS2's but are a LS6 head. The 243 casting number is shown on the
pics. Chevy dropped the lightweight valves for a reason-they had a TSB for
some failures-and i have seen some personally myself since i have an 02 Z06
and a few freinds with Z06's."

Hey bro-that's me! You can ask around I wouldn't be foolin yah-it's not the way I do things. You can confirm by pm'g JRP or J-rod that LS2 heads are LS6 heads.

HAHA!! ...the LS1 world is a small one. I'm gonna snag em up when I get back from lunch. Thanks.

He is right the LS2 and LS6 use the same exact heads and both has the casting number 243 on it.

Yeah casting is same...heads flow nicely stock but get em' p&p'd and you'll really fly!

I've never heard of the sodium filled valves going bad (or whatever it was), which is not to say it is not true, I just never heard anything but good remarks about it. The point of them being sodium filled was to help reduce weight and to dissipate heat (a good thing, helps ward off detonation).

Springs...I don't know. There are so many different colors and over the past 2 or so years, GM has been mixing and matching parts from engines. My 04' GTO LS1 has LS6 and LS2 parts in it!

How much is there to really be gained by P&P in an FI setup seeing some real boost?

If your going forced induction then the heads become less of a factor-you still need goods springs as boost can open the valve when its closed. For boosted applications the higher the spring pressure the better.

2001 LS6 springs are blue. 2002-2004 LS6 spring are yellow but I believe the early ones were green.