I thought they only came on z06's but today I was looking at my buddies new 07 chevrolet silverado with a 5.3l and it had 243 heads.Will someone please tell me what the difference between the truck head and the z06 head is?

 

The Z06 came with them, but with longer stem sodium filled/hollow stem valves than any cars after that. Then the GTO came with them without those valves, the CTSV had them, and now they are being used on some trucks. There may be more I'm forgetting at the moment

 

are they the same & will they work on an f- body

 

It's the same head, and yes it will work on an fbody

 

I heard the 243s from the LS2's wont work on a 3.9 LS1 bore because of the bore size... That the LS2 heads are meant for a 4" or bigger bore. Is this true? If they will work, that would be great cuz have a set that I can get ported...

 

thanks

 

 

Sorry to bring this back up but did the CTSV have sodium filled valves like the Z06?

 

Depends on the CTSV. 04-05 had LS6s which have sodium valves. 06-07 have LS2s which are just the 243 castings with the regular valves.

 

They do come on the Silverado as well as the LS2, except without with sodium filled valves. They do also have the yellow beehive valve springs that are good up to .600 lift as rated by the GMPP 2008 magazine. Good luck

 

I just saw some 243s today on a 2007 4.8 Silverado.

 

.600 is wishful thinking,
.545-.550 is more reasonable, if being used with lazy stock like lobes cam
02-04 z06 cam may be the most agressive u can go on the yellow springs
safely

 

agreed

 

You can get a new set at Scoggins for $640 for a pair with the yellow springs good for .580 lift. Hard to beat that deal...