I just purchased a set of Livernorris stage 1 243 heads, I also have a set of 2002 zo6 heads with approximately 10,000 miles. I was wondering if it is worth the trouble to switch the lightweight valves from the zo6 heads to the livernorris heads... What would this really gain other than having to buy different length pushrods as the lightweight valves are .6mm longer. Also I plan to resale the Zo6 heads and if they don't have the original valves i am sure that would decrease their resale value. any advice would be greatly appreciated. Thanks.

 

I think it is, but what did Livernois do to the valve seat? If they modified it then the valves may require some additional work prior to installation. A lot of this will depend on what type of cam/valvetrain you are running and whether you can get to your RPM goals with the solid valves. I have also seen some rumored information that GM went away from those valves due to issues with reliability, but have not seen and direct information that has come out of GM on this.

 

You could get Katech hollow valves.
Also what Vettenuts said is true, (GM LS6 valve reliability issue is questionable, there has been a few, very few reports but I've used these successfully for 3 years)

Lightweight valves will only be beneficial if you plan on spinning the motor higher than 6500. Only then does effective valvetrain moving mass start becoming beneficial. Below that is a waste.