sodium filled valves???
 

I just bought a set of 243 heads and found out after they do not have the sodium filled valves. What is the difference between normal and sodium filled? and should i go buy them before i put the heads on?

NOTE: this car is my weekend car, not a track car

Sodium filled valves are very light-the center is hollowed out for running high rev's. Not really needed for normal/casual driving.

are 243 heads not the stock heads that come on a standard c5?

241 heads were on base models. The Z06 received 243 heads.

The LS2 uses 243 heads with non-hollowed valves. Gotta be careful what the heads came off of, if you want the hollow valves.

The Hollow valves are about 90gr I think and the others are a bit over 100gr. Going off memoy here :D

You don't need the Z06 valves unless you really plan on 7k rpm speeds.

But, if you can find them cheap and install them, you might as well. :)

Perfect, thank you.

Welcome :thumbs:

I believe the 2002-2004 Z06 heads came with the sodium filled valves. The 2001 Z06 and all standard C5s did not.
Ed

Sodium-filled hollow-stem valves are about more than just weight reduction. In operation, the sodium liquifies, conducting heat away from the valve itself and into the cylinder head. The technology has been around for a very long time, mainly on truck engines in years past.

HTH

I remember the 1970 Buick GS455 Stage1 had them, so they've been around a while.