I have a 2005 2500HD that was manufactured Sept 2004. I was told a 2005 + truck LQ4 engine would have the better LQ9 rods. Can anyone tell me how to find out?

Thanks

 

Are the valley cover bolts 13mm or 10mm head?

 

Do the 13mm = better LQ9 rods?

 

I am just learning about these engines so I will have to ask what the valley bolts are ?

 

yup that means its a 04 or newer also IIRC
the bolts that are underneath the intake manifold were the knock sensors are mounted there should be 10 of them

 

I have not really looked but I am assuming the intake has to be off to see these ?

 

From what I've seen the engines with even length head bolts, and HD rods have the 13mm bolt heads. You can see a couple of them with the intake on.

 

I will take a look and see what I can see.

Wanting to put a set of 243 heads and an LS6 cam in my 2500 HD and was wndering if it had the bettr Rods due to compression going up. Any opinion on these mods? I am wndering if the head swap is really worth about $650 for a new set from GM?

 

2005 truck made in 2004 should have the big rod. The rods won't matter until you get past 750 HP. Actually the lighter rods are better for lower hp because they weigh 50 grams less. You can feel the difference in response...

 

not to butt in but i just got an lq4 drop out, from an 05 and it is 24x reluctor, short and long bolts, pressed wristpins and 10mm valley bolts