If so, then what is the difference between the 400HP ls2 GTO/Escalade 6.0 engine and the 345HP 6.0 LQ9 engine?

 

if you would put a set of 243 heads and the LS2 cam you would have identcial longblocks minus being Iron and Aluminum

 

What Heads And Cam Would Put Me Over 400hp And Give Me Good Drivibilty?

 

What heads are on the LQ9? And what are differences on the LQ4?

Thanks.

 

same heads LQ4/LQ9. 317 casting.
EDIT: LQ4 has lower compression pistons and slightly thinner rods. LQ9 has the beefier rods and slightly higher compression. I dont know the exact ratios.

 

on the LQ9/LQ4 both have the 317 heads which i hear are suposed to flow the same as the 243 heads but the 317 heads have a bigger combustion chamber which gives less compression.. damnit i wish i had the lq9 with 243 heads..that'll be my next motor i guess

 

The direct answer to your question is no, the LQ4 and LQ9 are GEN III iron blocks (closely related to the LS1 and LS6) while the LS2 in a GEN IV aluminum engine. There are some differences in the sensor placement and things like crank reluctor teeth, and I believe the cam position sensors are in different places (rear for GEN III and front for GEN IV), but those can easily be overcome with a little bit of work.

The new GEN IV iron blocks that are more LS2 based are the L76 and L92 IIRC.

 

here's the CR
LQ4 = 9.41:1
LQ9 = 10.08:1

and also the lq4/lq9 have the same pn's for connecting rods
pn 12568734

 

i thought the L76 was the rpo code for the aussie car based intake manifold for the L92 heads and L92 was the rpo code for the block (6.2L)

if im wrong could someone explain what the L76 is

 

I believe the heads are exactly the same (317 casting), but the LQ9 has flat top pistons where the LQ4 has dished pistons, which accounts for the higher compression ratio of the LQ9.