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LS LQ 9 ( from a 2002 Escalade)-- what we need from the donor truck to install into our 1988 K5

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riv1973

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Hi All!

so my son and i are doing a father son project on a 1988 K5 blazer with the 350 in it. my son has been junk yard hopping for parts for our truck and has found an engine we may want to use in an LS swap for this truck. the current engine is burning oil ( blue smoke on start up so might be heads and valves but not sure). he found a 2002 escalade with the LQ9 6.0 liter (345 hp version). the motor will be an over winter project. we have to inspect it and make sure it is a good motor. if we get this engine and all the wiring etc, should be also get the trans that is in the truck? if we go with the 4L80 ( I think) that is in the escalade, does the K5's transfer case work with the trans and engine combo?

i also need the stuff from the donor truck that i need. i have researched and it seems that i need the

TAC module,
PCM module
pedal assembly
all the 02 sensors
a/c compressor
full engine wiring harness
exhaust manifolds
all the coil packs

and am wondering if we should use the electric fans from the caddy/. also wondering if we should use the trans and transfer case instead of the one in the blazer.

my son is heading back to the junk yard tomorrow and i am trying to get him a full list of stuff to get. we would use the factory harness and keep the motor stock for now. we are planning an install over the winter but have an oppertunity to get this stuff cheap now.

any help would be appreciated on what to get from this donor. it looks totally intact and just got to the yard recently

thanks!

john
 
Well the transfer case from the Escalade will be drivers side drop so that won’t work if you’re keeping your axles. Me….I’d rebuild the 350 as a father son project…
 
If it were me, having never done an LS-swap, I would take everything the yard would let me for a given price. Everything connected to the wiring harness or engine/trans in any way. Doesn't matter if you scrap (or sell?) the extras later, you don't want to have to scrounge stuff down the road. Emissions, fans, etc.

From what I gather, the wiring harness will likely be something you either have re-worked by someone that specializes in re-doing the LS-harnesses for retrofit, or you buy a new one.

FWIW the Ford Windstar electric fans are the hot ticket in these trucks, they fit very well. No idea how they work with the LS PCM. Most modern OEM electric fans use weird mountings that make retrofit more work. But again, if you can basically gut the truck for the same price, do it. Figure your options out later, once you have all the components.
 
An Advance Adapter should have you mounting the Blazer T-case to the 4l80 then the factory Blazer driveshafts should fit right in with no modifications.
Just know there is some kind of trick to not having transmission fluid pass out of the transmission and into the adapter housing.
 
thanks guys!

so tuckerK5, what do you mean about the trans fluid leaking out of the transmission and into the adapter housing? is there a seal i have to get?

john
 
I bought my engine and transmission from the local GMC dealership.
They were also good enough to order the adapter and mount it to the transmission for me.
After I got it running there was fluid escaping the transmission into the adapter so I drove it up to the dealership and had it fixed under warranty so I don’t know the details.
I’m sure someone on here knows what needs to be done or the Advance Adapter folks should be able to clue you in.
 
I would find out what transmission is factory in the Escalade. I parted an '04 to get the LQ9 and it had a 4L65E. The 4L80E has a 32 spline output shaft which won't work with your 700R4 equipped NP208, it is 27 spline. You would need a 32 spline input gear for the t-case. Then you need a VSS output somehow for the transmission to be able to operate. NP208 cases don't have this capability, so you would need to find a VSS generator for the speedometer cable, or find a passenger drop NP241, then get the input shaft for whichever transmission you want to use.
 
Is there any evidence of 4L80s in Escalades? They are 1/2-tons, so the AWD one should have 4L65-E, right?
 
yes my mistake. it is a 4l65E.

Ok so i bought the engine. undecided on the trans but back to that in a minute. i think i made out well. motor and all the stuff was $600 and they took it out. trans would be another $300 if i get that.

i am going to build a test stand to run the motor on at home prior to install but i have some installation questions

i will be getting all the stuff with the engine ( wiring harness, power steering pump, A/C stuff and alternator). can all the accessories work with the 1988 chevy 350 stuff? can i use the 6.0 power steering pump with the power steering unit on the truck? can i mate the A/C compressor to the A/C stuff on the Blazer? i assume the alternator will also work as long as i get the right harness?

which is the best tranny to use? i can get the caddy's 4/65E for $300. should i use it or the 700R4 in the blazer now.

was thinking that a custom harness from one of the companies will be best. si that true? would have it set up for exactly what my truck has and what the motor has. thoughts?

will the oil pan clear? or do i need another pan to make it fit my blazer.

which motor mounts are best?

also it uses an electric connection between the gas pedal ( i got that) and the throttle body. can i use that and have that incorperated into the harness, get the one from the caddy or can you change to a mechanical linkage like there is in other 6.0 liter motors.

i will have more but this is a start!
 
You can use the power steering pump on the 6.0, the A/C compressor is too close to the frame rail from what I understand. Don't try and use the 700R4 if you AREN'T going 4L80E. Go get the 4L65E and let the electronics control both engine and transmission.

Be careful on the harness, I know that there is one on ebay that has something which causes a power draw and other things. I don't know the brand ATM.
 
so i have been looking at Holley which i have found out has a accessory bracket set up. if i can use the stuff i got from the car that will make it cheaper. all the stuff from holley is like $2300. that is with all the accessories such as A/C, power steering and alternator.

also i can get the same trans that went in the escalade and i thought that this would be good since they were born together and might work well together.
 
I personally would go get the Escalade transmission, and check out what's in the pan. If it doesn't look terrible, put a Transgo shift kit and a Corvette servo in it.
I would only buy a bracket kit for the A/C only, and reuse the rest. That's just me.
And I would reuse the factory ECM, unless installing a large camshaft, because my son has HP tuners. If you don't have that, or someone knowledgeable to go into the ECM, then consider the Holley system.

I would honestly check with @folkenheath and get parts through him. He works on this stuff and knows a great amount!
 
Thank you, I would be glad to help out with any parts you need that I can help with and any advice I can offer.

Holley and GMPP both offer accessory drive systems, I can get either depending on what's in stock.
 
folkenheath!

thanks man! we have the motor and trans at the house. we have everything including the TAC module, PCM, fuse box on the engine compartment side, MASS air flow sensor, the pedal and the plug that goes to the pedal ( i cut the wires but u have the plug and about 2 feet of wire) and it has the electric throttle set up. I am a little overwhelmed at this point. the harness is huge and has tons of plugs. i have been told to so a stand alone harness. do you have any thoughts on this?

also the motor seems to have high miles on it. turns over by hand well. but it is VERY crusty. we have it in our garage. just got it on the engine stand today.

How do i proceed with getting the ECM flashed ( the VAT--anti theft software--needs to be removed correct) and i am sure the PCM will need to be tuned to my set up ( 1988 K5 blazer.). i would like to run the factory air and any factory stuff i can. can you please help me! i am used to working on cars, just not these newer engines!

thanks man!

john
 
I would buy a new harness from current performance, psi makes a drop in peddle for the cab that works better mounting wise than the escalade peddle, engine mounts from Tejas, diy4x or ord. There are lots of options for having your ecm programmed to work with with out the vats which you need to have removed. I'm not sure if you need to clearance the cross member if you use mounts be sides Tejas.
 
Do you plan to change the cam or headers or anything else? Or it will be 100% stock?

I myself always switch it to aftermarket because it's easier and faster to tune, will tune itself most of the time, and you can change anything you want down the road and don't have to worry about whether it can handle it.

I also can't leave to stock because there is too much easy power to unleash with a cam and headers, not to mention the tune itself.

By the time you buy an entire different harness you are approaching an aftermarket control system with a standalone harness.

There are times when a stock computer makes more sense. I have to be honest, I don't have any experience using the stock computer for the vehicle. I don't leave anything stock except my daily driver family truck.

As for what to get from the donor truck, get as much as you can. Definitely get the coil packs and trans and Tcase adaptor if you can. The t case won't work unless you get a different axle as the front driveshaft is on the other side.

As for DBW or cable. Its a toss up and depends on what you get from the donor. Try to get as much as you can from the donor.

If you get an aftermarket controller, it will come with the computer, all the wiring(except the coil pack sub harness for each bank that is usually part of the coil packs, which is available extra). It will also come with a new 02 sensor.

The rest should be on the engine and transmission.
 
hey man!

i have been thinking about whether to leave stock of not. not sure which way to go. i think i will go with some kind of header because the stock ones are junk. also the engine looks to be very high mileage. i have seen stock LQ9 long blocks from GM for $3600. looking to see what a machine shop will charge for a rebuild. i have all the stock electronics. now we have to decide how modified to go. how much can you reprogram a stock computer and what is the limit of what you can do with a stock computer. can you also use the stock wiring harness and change the computer?

i am torn with going stock and changing one thing at a time VS a total rebuild and all at once. if it is a stock motor with some tuning and exhaust headers and 2 1/2" non cat mandrel bent system, i wonder what we can get?

i have been looking at the stuff you guys talked about and i am on my way to figuring all this stuff out. first thing is to build a test stand.
 
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