I have a new set of LS6 heads with valves and springs (GM part number 12564824) and am wondering if valves are interchangeable in new factory head assemblies. I assume that they are because individually fitting or lapping each valve would be expensive. I know that after heads have been in use that valve locations must be preserved but I am curious about new heads.

Thanks, Gary

 

I'd lap them in just to be sure. You can't be certain they were all done exactly the same during production.

 

..the new ls6 valves are hollow sodium-filled units that are significantly lighter than the stock ls1 units...they are also a tad longer than the ls1 units they replaced...

therefore, i would be careful about interchanging them....procede with caution....

 

They will work just fine. Just lap them in and make sure you check the installed heights on the springs.

Jason

 

i guess thats how the LS6 gets away with using the same pushrods as the Ls1, with a diffrent BS camshaft. i always wondered that.

 

Yep that should explain that!

 

Jason -

What should the installed height of the valve stems be?

Thanks,
Gregg

 

The LS6 2002 and later valves are 6mm longer than the stock ls1 valves.

...were you contemplating swapping the new valves to different cylinder locations in the new head; why?

I swapped springs on my new ported heads and later learned that some sellers will void a warranty for this and any other mod to "their" head ... ...since the LS6 springs are not all that good for high lift cams I have no regrets, however...