Goldhawg

iTrader: (7)

My 99 2dr tahoe proceeded to make significant internal engine noises literally the day after I did my 0411 PCM swap to run efans. I'm thinking that it was asking for the whole LS swap, so now I have a 54k mile LQ9 I bought. Unfortunately while miles are low, engine was from the rust bucket area of Ohio, so the block has a lot of rust. Any suggestions on how you would clean up the rust prior to painting the block? How 'bought the best way to prep the aluminum like the water pump and the cam cover plate (forget what you call it).

Also, I plan on using my existing 4L60E, but I've been reading about the converter issue, and I think I need a spacer or possibly a whole new flexplate. But most of the discussion seemed to be around those w/5.3's and seemed that 6.0's were different. Does anybody know ground truth here?

Next up, I expected the '02 throttle body to be DBC but it was already DBW. Will any DBC throttle body bolt up? I want to stick with DBC to make the swap easy from the vortec.

Finally, I had also just upgraded my exhaust to a single 3" Gibson exhaust with the vortec. Can the LQ9 benefit from long tubes if it ultimately is going out a single 3"? Anybody know of other header options with OBS 4WD setups?

superdave84

For the engine, you can get some chemicals that eat the rust, but in my experience they don't work very well. I would degrease it thoroughly, and use a small wire brush to clean it too. Then use a rust converting spraypaint. You'll find that in any auto parts store or Home Depot, etc. After the paint turns black (some brands are black right out of the can), spray with engine enamel and top coat with an engine clear.

Your 4L60e from '99 is most likely going to be the wrong trans. I think it's possible to get it to function somehow, but the electronic controls are different, and your harness will not plug into it.

Goldhawg

iTrader: (7)

Appreciate your thoughts on the block painting. But I know the current 0411 PCM controls the tranny fine; its doing it now as I just completed the swap over to the 0411 PCM prior to my vortec grenading. The issue seems to be the converter distance per this post:
http://www.pirate4x4.com/forum/11065304-post1.html

I think I have the flat flex plate (but I'm not really sure I understand what part is supposed to be flat and which is dished), so I think I only need the spacer? I also have a 2010 auto flex plate if that would work better.

Any ideas on the header and DBC?

superdave84

I am unsure about the spacing, however I did have a problem when I did my 5.3. My issue was that I used a 4L60e and converter from a car, and the 5.3 is obviously from a truck. When I put the assembly together, there was definitely a space there....more that what there should have been.

I ended up scrapping my 5.3 project and switching to an LS2. When I mated the LS2 to the 4L60e, it was perfect. You MIGHT get lucky and have your truck motor bolt up to your truck transmission. If it were me, I would pull the trans out and mate it to the 5.3 outside the vehicle. You should be able to see if it's right or not right away. swap the flexplates or use spacers if needed. I am not comfortable using spacers there, but that's just me.

Headers, no...no idea. My gut tells me long tubes are going to be better, but running it through 3" single...not sure if it's worth the money. Personally, I would get the Pypes universal 2.5" X-pipe and run duals. That's what I did...I think I only paid like $120 shipped and it's all stainless.

I am not really schooled on throttlebodies, but there is a 3 bolt version and a 4 bolt. The trucks at least USED to come with 3 bolts, as did the LS1. Newer truck motors might have 4 bolts, I have no idea. If you are looking to keep the truck intake, you might be stuck with a 3 bolt TB. If you swap out the intake you might be able to switch if needed. I know the LS1 accepts the truck 3 bolt TB. LS6 intake might as well. But I think the 3 bolt cable operated ones are going to limit your power because they are all smaller. If you have insane amounts of money, you could look into the Fast intake. I have seen them with their Fast TB...it's cable operated and I think it's 90mm or 102mm or something like that

gofastwclass

iTrader: (2)

The transmission thing is VERY simple and there is a lot of confusion and misinformation on it. As such people spend a lot of money where they don't need to.

• Any Gen I / II (non LSx) automatic transmission needs a spacer between the crank and converter snout, to mate to a Gen III / IV engine period. The exception is the 1999 Gen III 6.0 with iron heads which has a .400" longer crank. Dished or flat flexplate doesn't matter, it's all about where the spacer sits in relation to the engine and flexplate.
  
• Any Gen III / IV (LSx) transmission does NOT need a spacer to mate to the same class of engine.

• If you have a DISHED flexplate and a Gen I / II transmission you need to install as follows: engine, flexplate, spacer.
  
• If you have a FLAT flexplate and a Gen I / II transmission you need to install as follows: engine, spacer, flexplate.

The spacer is the ONLY change here.

For electronic controls, late 1997 (three piece case) and newer 4L60E's are able to be controlled by all Gen III PCM's and some Gen IV TCM's. These will have PWM stamped on the front pump area, a top bolt hole and a round plug.

Early 4L60's have a square plug and can NOT be controlled by the PCM. Middle (transition period) two piece case 4L60's have a similar round plug but the internals are different and can not be controlled by our PCM's.

As a side note: if you have a Gen III (with the top bolt hole) transmission everything on it is metric - including the torque converter bolt pattern. This means the converter holes won't align which you can die grind out 2 or 3mm to fit (done several times on street cars) or drill new holes.


Your 2002 DBW throttle body will interchange with your 1999 DBC throttle body without issue.

Many F-Body cars use a singe 3" exhaust and they make gains with long tube headers.

aknovaman

iTrader: (7)

I am compelled to add this. DONT drill the block for the bolt at the 1-o'clock position for the trans bolt. You will hit the water jacket and ruin the block.

ls1nova71

iTrader: (4)

Just to clarify things, a '99 Tahoe will have a gen1 small block in it, and the throttle bodies are different from the gen3's. You will need a TB from a '99-'02 Silverado, '00-'02 Tahoe, suburban, Yukon, ect, Express van from '03-'07, or F body '98-'02.

gofastwclass

iTrader: (2)

Good catch on the clarification ls1nova71, I was referring to Gen III engines only. I can see how some may be confused since 99 was a crossover year depending on the vehicle.

Envy

There is a lot of good information in this thread, and all over the net about this swap. It's probably one of the easiest swaps that you can do.

Your 411 PCM will run the LS (Gen III/IV) motor, provided you reflash it with a LS tune, the L31 (Gen I/350) tune won't run the LS motor. You can either modify the existing L31/350 harness and add some additional plugs, or you can just start with a LS harness, as you'll have everything you need and remove what you don't. Most of the Gen III sensors are different, so you'll need Gen III sensors to feed Gen III PCM, I don't think anything for the L31 will bolt onto your 6.0. Also, since you have a 6.0, to my knowledge, the LQ4/9 never came with a 4L60e, so you'll need to have whomever does your PCM flash, you'll want to tell them you're using a 4L60e as it's a different tune than the 4L80e.

As far as putting it in place, you can do it several ways, but if you buy the LS adapter plates, you can bolt your factory L31 mounts up to the plate, and the plate bolts onto the 6.0. It should sit realively in the same spot as the L31. With it bolted up into place, if you opt to use AC, you will need to re-use your L31 AC compressor, and get a relocation mount to move it higher than it sits on the LS truck, which would interfere with the L31 frame rail. The other option is to notch the frame, but I myself am not high on it, nor have I heard great feedback from doing it this way. The L31 4L60e will bolt up to the 6.0, provided the bolt hole in the 1 o'clock postion isn't used, and as stated above, don't bother drilling and taping it. Most of the time the 6.0 should have a spacer between the flexplate and crank that creates an additional ~.5" of space to make up for the 300mm on the LS style torque converters, so technically your current L31 torque converter will work if you buy the flywheel spacer and bolts, or you could buy the 6.0 flexplate with the spacer attached already, but since it's being attached the the 4L60e, you may have to modify the 6.0 flextplate to bolt up to 4L60e since no 6.0 came with an 60e. You'll obviously need to modify the existing Y-pipe for the newer style of manifolds, but should have the existing framework to modify rather than re-inventing the wheel.

Easiest option for fuel is to run a converter filter/regulator so you only need to feed the engine with one hi-psi line, the further you do this towards the engine, the less you'll have to plumb. Many of people have had a problem with the plastic quick disconnects, and they have melted down their entire vehicle/projects.

Most of your guages will continue to work, and can be adapted to recieve new signal, like tach, water temp, oil pressure, etc. Spend some time getting familiar with the wiring, and you will begin to see how the two are similar, and different at the same time... but as it was stated, it's fairly straight forward, and has been done several times if you look around.

Goldhawg

iTrader: (7)

Envy--
Thx much for detailed (beyond what I asked!) answer. I will start another build thread when I get closer.

I have already purchased Beertester's mounts that are supposed to put the LS engine exactly in the same location as the L31.
http://www.ls1truck.com/forums/lsx-t...-brackets.html

I have also purchased Lextech's AC bracket relocation to use all my existing accessories:
http://www.ls1truck.com/forums/lsx-t...acket-kit.html

I was also thinking about sending Lextech my stock harness and the LQ9 harness, he would integrate the two (I had already repinned the stock harness for the 0411 PCM) and I already have my efans working properly

My goal: figure out all the details so I can complete the entire swap in two weekends and the week in between (when the harness would be off for rework and I'd be building a custom exhaust).

ls1nova71

iTrader: (4)

Lq9's never had 4l80e's behind them, the LQ4's did, Escalades have 4l65e's IIRC. So your flexplate should work, you should only need to add the spacer.

mattdbal

Not to threadjack, but the guy I got my 5.3 from gave me a trans from a 98 truck. It has the two piece bellhousing, but not the right shaft like stated above. All I will need is the spacer to work with my 5.3? Will the stock truck harness be able to work with the 98 4l60?

Goldhawg

iTrader: (7)

Another stupid question: how do you get the truck fuel injector connectors to release? I read on another post that you pull back the locking tab, and push the connector toward the fuel rail and then pull it up, but mine aren't moving with reasonably hard force and some wiggling. I'm afraid of breaking this. What am I doing wrong?

aknovaman

iTrader: (7)

Remove the grey retainer clip by pulling it away from the wires, then pull it out of the injector connector completely, away from the engine to completely remove it. Then squeez the injector clip, push the connector toward the engine and then gently off the injector.

If you yank it off the injector before squeezing the tab, the loop that is over the injector tang will break and nothing will keep the clip on the injector.

gearjammer80

I know this thread is a few months old, buy I have a question. I have a 98 Tahoe 4l60e. Will the torque converter out of a 2000 4l60e work.