adrynalinjunkie

iTrader: (4)

What are the differences between a Gen III and a Gen IV LQ 4's ?

Is a gen 4 any better?

fastsspr

iTrader: (49)

I have the same question!

Bo185

The LQ4 and LQ9 are Gen III engines. Starting in 2007 GM switched to the Gen IV motors and had carryover Gen III LQ4/9's in the carryover 2007 GMT800 trucks.

All the GMT900 truck got Gen IV motors. The Gen IV LY6 6.0L replaced the LQ4 and the Gen IV L76 replaced the LQ9.


The Gen IV motors have VVT, front mount cam sensor, AFM (model dependent), and side mounted knock sensors among other things.

Is the Gen IV better well yes the LY6 and L76 and L92 all have the good flowing heads!

pillagenburn

iTrader: (2)

I went from a F13 cammed, full bolt-ons and tuned LS1 that dyno'ed over 400rwhp to a LY6 with full bolt-ons and a tune that probably dynos the same. What I can tell you is that the LY6 is more powerful, more practical, more fuel efficient and, in the real world, faster in every single way.

AES Racing

iTrader: (6)

LY6 is good if you're installing an iron block into a 05/06 GTO

the early iron blocks seem to be best in terms of quality, I don't think i've ever seen an early style iron block cracked bore, seen 3 new style iron LQ9s cracked bore. Overall issues with iron blocks are limited.