G.I. Turbho

Hello all,

As it sits currently, my brain (much like many others), is running in a hundred different directions. So I will try to start where it may make the most sense.

My 2008 5.3L Flex Fuel Tahoe with a 4L60E, and 3.73 rear end gears (I know, I have done some searching around the LS1Truck forum as well, but I like the crowd here), decided to puke the #2 piston out the oil pan on Father's day this year. So.......I decided I'd snoop around for a new engine, and while I was at it, would slap on a turbski. So I found a BW S366 T4 w/ .88 A/R, 66/73, and upgraded thrust bearing to help make some extra go fast. I would ultimately like to keep the vehicle in sleeper status, with all functions of the truck in stock form. It will be daily driven, between 6-8 psi, or maybe 10ish if see something to play with, to try and keep the reliability factor. I know the engines are very capable, but I don't need the reliability issues with mad boost and a hungry foot.

Fast forward 1 month:

So....I found an '06 Escalade (LQ9 w/4L65E- I only grabbed the engine) with 120-130,000 miles on it in a local yard. They said $1000 for engine from top to bottom with harness, and ECM. I pull the harness, and they pull the engine. Seemed legit, so I pulled the trigger on it, and it's now completely gutted out in the garage. Everything looks to be in good shape, and my excitement is ever growing.

My first of many dilemmas is the compatibility between the '08 Tahoe harness/ECM (E38- pn# 7630/2384) running the LQ9, or the '06 Escalade harness/ECM (Warren- pn#9463/9162) running the LQ9. I will be purchasing the HPTuners VCM suite to further add to the insanity.

My thoughts on this one are as follows:

From what I can comprehend, the E38 ECM is very capable, and likely a better ECM (not to mention the stock '08 Tahoe ECM) for the build. I would like to run the stock Flex Fuel injectors (decapped/tested- could be a shot in the dark if they all flow within tolerance- idea came from a Denmah video on his decapped injectors) in the 5.3L intake, or swap them into the 6.0L stock intake. Figured the harness wouldn't create to many issues in the injector department, and the ecm may only need adjusted to new flow rate. The other option is to find aftermarket/used injectors, and hope they are just fine. The throttle body on both intakes are DBW, so if there is a connector problem or foot pedal compatibility issue, I may be able to swap throttle bodies. I'm also looking into a boost regulated fuel pump to further assist, but we will see what I can get away with.


Moving on, I have come to the Valvetrain/Heads. I will be leaving the heads almost completely untouched (although I am currently debating an at home porting/polish job). I'd like to leave the valvetrain untouched, but I do know that I'll be needing to swap out the cam gear, cam sensor, and front cover, to accommodate the newer 58x/4x reluctor combo needed for the E38 ECM. And it is with that in mind that I have a few questions.

Will I be able to use the front cover, cam/cam gear, and sensor from my 5.3L on the 6.0L LQ9? Or is the LS2 cover the only one that swaps out? And if that's the case, why only the LS2 cover?

-my thoughts are that the stock harness already has the cam sensor location on the front cover (so no need for an adapter/extension), the cam may be a drop in, and the gear will come with it. If that works, then all I'll need is a 58x reluctor for the crank, plus I can maybe swap the crank position sensor into the LQ9. And on that note, if the 5.3L crank is good, could I swap them out? I'm really thinking I'll just buy a new reluctor and get it pressed on the 6.0 crank. To try and keep from the Frankenstein of a rabbit hole I'm going down.


And to move a little further down, and into an area that will keep much of its stock integrity, the rotating assembly. I only plan on changing the pistons rings (few strokes of the ball hone and regapping for boost), changing the rod bearings, and changing the main bearing. I may run new but stock hardware, but I think the stock hardware down there should be just fine.
- I did want to put ARP hardware in the bottom end, but hadn't realized there would be added machine work with the rods, and the mains. So my budget has decided against it.


I have also contacted (I don't know if we are allowed to give a "shameless" plug or not) WS6, and will be purchasing their top to bottom gasket/seal kit w/ upgraded barbell, with some other (cough) piston rings, and (cough) rod/main bearings, to freshen up the engine. There may be some other things needed, but I'll play it by ear.

I know that there are many things I should do to this thing while I have it out, but the budget is what the budget is, and as it sits, I'm having a hard time not giving her more. The other side of me wants to leave as much alone as possible (while really just "freshening" up the motor), and running her in true form. Well, plus a turbski.



Well.......I'm sorry if this is a book, but for one, I needed to get these thoughts out of my head, and I figured this was the place to do it. And for two (hahaha), I need to get my post count up so I can reply without having to PM everyone. If you have questions, or would like to set me straight on some things, I'd love to hear it.




Thanks for the patience

ryeguy2006a

iTrader: (27)

I think that the bigger issue that you may have is that your crank reluctor ring is 24x and not 58x. Check the color of the crank sensor black is 24x and tan is 58x.

Also, if you want to keep your vehicle in stock function I believe you will need to keep your stock ECU or you will have lots of lights coming on.

G.I. Turbho

Thanks for the response. From what I have gathered, the stock ecm is the one I'll go with. I'll do a 58x conversion, and run with it.

There are just so many options you know.