Currently, I have an Drive By Wire LQ4 6.0 in my 05 RCSB truck. It has been upgaded with stock 243 heads off an 08 NNBS 5.3, a TSP 224-112 cam, PAC 1218 springs, TSP 7.4 hardened pushrods, 160* thermo, LT's, no cats, dual 2.5" exhaust with x-pipe and a Volant CAI. The truck pulls pretty hard up til about 6000rpm. I still have the intake off of the 08 5.3 I got the heads from, and I've been reading that the NNBS 5.3 intake is the same as the TBSS intake, which is good for 15ish rwhp on a setup like mine and will pull higher up in the rpm's. Would it be worth it to put the 08 intake and tb on my LQ4? I know I'll need an X-Link, but what else? Also, My factory fuel injectors are being maxxed out and leaning out my afr past 5200rpm, so I need to change them while I'm doing the intake swap. So, I need to know what injectors I should buy for my setup that will easily support my power levels and be easy to tune for as well as plug and play, without spending a ton of cash? What all will I need to swap the NNBS intake and bigger injectors in? I will be retuning myself as I have HPTuners, but I've never tuned aftermarket injectors before . My goal is to hit 450rwhp with my current mods plus a tbss intake and some port work on the heads. I know with my cam and a tbss intake, I should spin it up a lil higher (shifting at 5900-6000 now), but I popped a bone stock LQ9 about a year ago shifitng at 6k. Looked to be stretched rods or rod bolts due to high rpm. Completely trashed my block, driver's side head, dropped 2 pistons and the other 6 had valve marks on them . So, I'm a little scared to push this setup past 6k. I was thinking maybe some ARP rod bolts and an LS2 timing chain for reassurance on the 6200-6300rpm pulls without spedning a ton of cash . Can rod bolts even be installed without pulling the motor from the truck? Sorry for all the questions, but I had abunch of thoughts on the intake and injector work I'm about to do and the related rpm/power increase! Thanks in advance guys!

 

If you have the TB this swap is literally almost a plug and play. You will need the X-link like you mentioned, and thats about it. Your fuel system is already a returnelss, which simplifies this. I'm about to do the same swap on my 2005 Sierra Denali next weekend, so I can give you more of a heads up then. Does your intake have the fuel rails already in it? I think the 08's were flex fuel trucks, so your new injectors are already bigger (ive heard 36# in flex fuel 5.3's) which covers that issue. You will need to buy either new injector pig tails, or the adapters to make the new injectors work though.

check out this thread:
Tbss Intake Swap: How To - SilveradoSS.com

 

The 8.1marine are a direct swap and flow 44#. That's what I have in my NNBS intake.

 

Vortec-Yes, i havethe complete NNBS intake manifild assembly. If it does have 36# injectors and they would cover my power levels, that would make my day! Cause injectors are expensive!!! Where should I buy the X-link and injector adaptors?

 

So all I need is intake gaskets, an xlink and injector adaptors?

 

your tuner should be able to tune for the injectors.
Check out Katech.com. They have the injector adaptors.
and the x-link: Torque Rush LS2, LS7, LS3 to LS1 throttle body adapter harness

 

So looks like $225 for a new xlink. And iirc correctly, the intake gaskets are about $70 for the set. So how much will it cost me to hook the injectors to my harness?

 

Do I even need the injector adaptors? Thatd save me $70 if i dont need em. And what intake gaskets should I buy? Stock for a 6.0 or stock for a 5.3?

 

And where would I get the data to input into HPTuners for correct fueling with the flex fuel injectors? Ill be doin the tuning myself...I verified today that the intake I have is loaded with 07 GM Gas/Ethanol injectors! So these are the 36lb/hr ones right? I know my fuel system will hook right up, but what about the purge solenoid and other elctric devices on the intake? Will they plug up? Or will I need to use some of my old parts and adapt some things?

 

Since I'm using stock GM injectors, could I just copy and paste all the injector tables under Engine>Fuel>General from a 2006 Stock Flex Fuel tune into my tune and everything should be on-line and fine then? Cause I've spent ALOT of time tuning this truck to get it to idle and drive nice and don't wanna screw it all up!