I'm a little late to the party so I'm askin' y'all in the know. I know that the new 5.3's have the TBSS intake manifold but I also heard something about the heads. Are the new 5.3's packin' 243 heads off the LS6? That would rock...........
Thanks

 

YEP! They're either packin those or the 799 heads. But they are both the same head. The only difference between the truck heads and the actual LS6 heads are the springs and they dont have the sodium filled valves, which the LS6's do.

 

Thanks, Freek. One more Q; what with the 243's and all, doesn't that affect compression? And if so- would I be better off with some ported, TEA 5.3 heads........

 

The new 5.3's also have flat top pistons... I think they are close to 10:1 compression now.. But yes, if you put the older 5.3 heads on you would gain some compression. About a half a point.

 

Ahhh, flat top pistons; that's the difference. Well thank you very much..........

 

No prob!

 

can you verify that the 5.3 is 10:1? i thought they were 9:5:1 considering the 6.0 is a 10:1 and the L92 is a 10:5:1 just curious bc ive never seen any type of info on a Gen IV 5.3 having that kind of compression

 

don't know about the Gen IV but the Gen III 5.3 L33 with flat top pistons and 799 heads is 9.9:1.

 

9.95:1 As stated in my service manual.

 

SWEET i always thought they had 9:5:1 but thats good that it has such a high compression.