It will be your best option. installed and all it may cost you 500 bucks more than a head job...but you have the 6.0L you want and its an LQ9.

 

im going down tomarrow to check it out. if all looks good im gonna buy it.

 

Yeah the LQ9 has flattop pistons vs the LQ4 has dished...

 

So I looked at the motor and it looks all good. I put a deposit down and gonna pick it up Monday. The only thing I notice is different is that its a drive by wire engine and my truck is a drive by cable. Is this a big deal or a simple fix? Would I just need to put the throttlebody from my 5.3 on there or are they different on 6.0,s

 

You have two options on the throttle, put a TAC throttle pedal(drive by wire) and run the wiring for it or your throttle body off of your 5.3 might fit it, and the wiring for the TPS sensor is already there. Either way you are going to need to retune the PCM for the 6.0 so check the bolt pattern on the other intake and check because the setup you have now is a alot less work.

 

Oh yeah and the most likely problem with your 5.3 is the heads themselves. GM had an issue with the castings cracking near the the head bolts. if you remove the valve covers and look near the bolts you can see the obvious clean spots. if not you can pressure test and and look for the coolant.

 

I was gonna mention that...but I thought the Castech heads that have this issue were used only on 03-06 5.3 and 4.8L engines....I could be wrong though

I know there is a TSB on it.

 

Just swap your intake and throttle body on to the new engine and keep it simple Don't forget that your PCM will have to be retuned. If you search either this section or the internal engine mod section, there was a thread with pics of the heads that crack, if you're interested. It's kinda mute since you're upping to a 6.0

 

That sounds easy enough. I wouldn't lose any performance with the 5.3 intake would I? Would I need the 6.0 injectors or are the 5.3 injrctors the same?

 

Stock injectors are a different part number, but if you swap intakes and rails you can use the 5.3 injectors. They should have the same flow rate, I believe they just look different.