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Old 04-05-2023, 08:32 PM   #1
bcfishon
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My ls swap game plan

My first ls swap
Victim is my 67 GMC k10
Currently has v6 and manual 4sp with 205 transfer case
Going in with 06 Tahoe 5.3
Motor and transmission are out
5.3 is now mated to 4sp
Will use square body motor mounts/crossmember(4wheel drive)
Will Fab swap mounts for motor
Will run factory gauges for oil ,speed & water
purchase a 3 wire standalone harness
Will use water pump fan and factory radiator
And all the rest will fall into place
Am I just fooling myself or is this a adequate game plan?
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Old 04-05-2023, 09:32 PM   #2
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Re: My ls swap game plan

well...its a start..!!! your on the right track
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Old 04-05-2023, 10:09 PM   #3
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Re: My ls swap game plan

Quote:
Originally Posted by mongocanfly View Post
well...its a start..!!! your on the right track
Thanks for your support!!

I'm assuming a aftermarket stand alone harness will have the charging system that will feed in through the battery terminal on the starter.

The harness I was looking at has two hot wires that go to the battery terminal on the starter with a ground on the head and a ground near the battery,has a relay that contains the hot for the ignition and relay for the fuel pump and a fan,rest of the connections are for the sensors and what nots. I think I'm gonna buy it and I'm hoping it operates the battery charging system as I described above,unless I'm wrong on that charging concept.
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Old 04-05-2023, 11:03 PM   #4
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Re: My ls swap game plan

what harness are you looking at?...the harnesses ive used have all the engine wiring, including charging.. 1 constant 12v, 1 switch on /cranking 12v, and 2 grounds
the original starter wiring curcuit for your truck will hook up to the LS starter
the ecm will need to see water temps, ive been drilling and tapping the pass side head for the gauge sender, youll need to have somewhere for the steam port to tie back into your cooling system, and youll have to add O2 sensors to the exhaust
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Old 04-06-2023, 12:41 AM   #5
bcfishon
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Re: My ls swap game plan

Quote:
Originally Posted by mongocanfly View Post
what harness are you looking at?...the harnesses ive used have all the engine wiring, including charging.. 1 constant 12v, 1 switch on /cranking 12v, and 2 grounds
the original starter wiring curcuit for your truck will hook up to the LS starter
the ecm will need to see water temps, ive been drilling and tapping the pass side head for the gauge sender, youll need to have somewhere for the steam port to tie back into your cooling system, and youll have to add O2 sensors to the exhaust
I'm looking at a harness from a Facebook maker, I think its basically the same design you descrbed and there seems to be no end to the sources and brands and prices on these things. I think I have a radiator with a return port and I have adapted the passenger side head to accept the original temp sending unit and I still have the drivers side available for the ls signal to computor. I've been thinking about the 02 sensors and was thinking I could weld in a bun somewhere right below the collector on some cheap Amazon block hugger headers. I think the block huggers will work best for connecting up the old
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Old 04-06-2023, 12:24 PM   #6
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Re: My ls swap game plan

don't hurry the project. go at a pace that you enjoy the rebuild. Take notes and take time to do it right the first time because going back troubleshooting is the tough part of the project. Temporary hookups and the old I'll make it better later is not a good plan.
GOOD LUCK
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Old 04-06-2023, 04:54 PM   #7
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Re: My ls swap game plan

I haven't bought any LS swap harnesses on Face book. On my LS swaps I've used Speartech and Howell with good success. I buy the ECM/TCM from one source so if there is an issue I have one supplier to talk to. They also supply a base tune so it will run once you get that far. I would suggest a chassis tune to really dial it in.
The alt charging cable should run from the main lug on the starter over to the main lug on the starter. None of the harnesses that I've ever used had that cable integrated in to LS swap harness. I typically run a 6 gauge cable from the starter lug to the alt lug. The swap harness should supply a single wire to the plug on the back of the alt.
The 2006 engine could be a a 24 tooth or 58 tooth crank reluctor wheel. You to confirm before ordering a harness. 24 tooth cranks need one ECM for engine and trans. The 58 tooth cranks needs an ECM for engine control and a TCM for 4L60E control. Crank tooth count also makes a difference in regards to the TCC/brake light operation.
Are going to run the 205 TC? Does the speedo cable run off the 205 TC? Do they make a 4L60E to 205 adapter? If you are using the 4L60E it will have a port for the VSS signal.
And you can't have enough good grounds. Battery to engine. Engine to frame.
Good luck with your project.
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Old 04-06-2023, 06:28 PM   #8
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Re: My ls swap game plan

In the middle of doing mine. I just got the LS engine running outside of the Squarebody to make SURE it was operating as designed and I wouldn't have an issue upon fire up. Since the truck will be more modern with Fuel injection, cruise and etc. The truck had neither of those when I got it. Truck receiving the transplant is in the background.
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Old 04-06-2023, 07:08 PM   #9
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Re: My ls swap game plan

Quote:
Originally Posted by bcfishon View Post
Thanks for your support!!

I'm assuming a aftermarket stand alone harness will have the charging system that will feed in through the battery terminal on the starter.

The harness I was looking at has two hot wires that go to the battery terminal on the starter with a ground on the head and a ground near the battery,has a relay that contains the hot for the ignition and relay for the fuel pump and a fan,rest of the connections are for the sensors and what nots. I think I'm gonna buy it and I'm hoping it operates the battery charging system as I described above,unless I'm wrong on that charging concept.
A 2006 Tahoe will have a GBCM (Generator Battery Control Module) that controls the alternator, which most aftermarket harnesses will not have any connection for. If left unhooked, it will charge at a default charge of around 13.4v all the time. If you want to keep the PCM controlled alternator, and if you haven't bought anything yet, the easiest way would be to go to an 03-04 PCM. However, you will also need the matching year TAC module and alternator. Some have said you can hook the GBCM up without the connection to the BCM (Body Control Module) and have it work, but didn't work for me.
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Old 04-06-2023, 07:58 PM   #10
bcfishon
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Re: My ls swap game plan

Quote:
Originally Posted by LS short box View Post
I haven't bought any LS swap harnesses on Face book. On my LS swaps I've used Speartech and Howell with good success. I buy the ECM/TCM from one source so if there is an issue I have one supplier to talk to. They also supply a base tune so it will run once you get that far. I would suggest a chassis tune to really dial it in.
The alt charging cable should run from the main lug on the starter over to the main lug on the starter. None of the harnesses that I've ever used had that cable integrated in to LS swap harness. I typically run a 6 gauge cable from the starter lug to the alt lug. The swap harness should supply a single wire to the plug on the back of the alt.
The 2006 engine could be a a 24 tooth or 58 tooth crank reluctor wheel. You to confirm before ordering a harness. 24 tooth cranks need one ECM for engine and trans. The 58 tooth cranks needs an ECM for engine control and a TCM for 4L60E control. Crank tooth count also makes a difference in regards to the TCC/brake light operation.
Are going to run the 205 TC? Does the speedo cable run off the 205 TC? Do they make a 4L60E to 205 adapter? If you are using the 4L60E it will have a port for the VSS signal.
And you can't have enough good grounds. Battery to engine. Engine to frame.
Good luck with your project.
Shortbox, the 205 tc has a spot for the cable driven speedo and I'm running the manual transmission, I will do as you suggested and connect alternator to the battery terminal on the starter. I have a black crank sensor and if I understand correctly this means 24 tooth, and yes grounds,bad grounds have been a a source of many problems when I was younger. I appreciate all the assistance from everyone on this site and only hope I can continue to contribute as my knowledge continues building
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Old 04-07-2023, 10:19 PM   #11
LS short box
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Re: My ls swap game plan

Since you have a a 24 tooth crank it might be easier to run a DBC throttle body instead of a DBW? I've run the 2002 Camaro throttle body on a number LS swaps. No need for a BCM. Don't know if that works on a truck intake. I've always used an LS6 intake on my early LS swaps. My 98 Wrangler with a 2002 Camaro LS/4L60E swap charges just fine even when using the snow plow. 14 years on the swap zero issues. Howell LS harness.
Same for my 68 C10 LS6 /4L60E swap.
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Old 04-08-2023, 12:25 AM   #12
bcfishon
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Re: My ls swap game plan

Quote:
Originally Posted by LS short box View Post
Since you have a a 24 tooth crank it might be easier to run a DBC throttle body instead of a DBW? I've run the 2002 Camaro throttle body on a number LS swaps. No need for a BCM. Don't know if that works on a truck intake. I've always used an LS6 intake on my early LS swaps. My 98 Wrangler with a 2002 Camaro LS/4L60E swap charges just fine even when using the snow plow. 14 years on the swap zero issues. Howell LS harness.
Same for my 68 C10 LS6 /4L60E swap.
I have a fuel pedal bracket fabbed up for the dbw fuel pedal and my wiring is routed into the engine bay,I plan on mounting the ecm between the battery box and fender,I would be Leary to deviate from the stock setup with my experience.
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Old 04-10-2023, 11:28 PM   #13
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Re: My ls swap game plan

One of the more difficult issues to solve, for me, was the adaption from the metric power steering pump to the stock power steering. The angles didn't allow for any adapters in the mix.
Cheers
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Old 04-11-2023, 02:09 PM   #14
kglowacky
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Re: My ls swap game plan

I had new lines made with
fittings installed on each side of the new hoses ps lines made using the metric and stock fittings to make the hook ups. Had it done locally
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Old 04-11-2023, 05:54 PM   #15
bcfishon
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Re: My ls swap game plan

Quote:
Originally Posted by Accelo View Post
One of the more difficult issues to solve, for me, was the adaption from the metric power steering pump to the stock power steering. The angles didn't allow for any adapters in the mix.
Cheers
I was fortunate enough to have already converted my rig over to a hydraboost brake and power steering so I think it will come together without too many problems. The news for the day is I was able to sandwich the motor in and it is one tight fit,I did end up using a dingo x member I had available. I probably should have moved the transmission and transfer case forward one inch from the previous v6 location,I'm right up against the firewall. I'm a little worried about water intrusion on the ecm with my mounting spot beside the battery box,may have to encase somehow. I got the ecm sent out today for a flash and hope to weld up some exhaust while I'm waiting for it to return. Things are moving along and I think soon I will be ready to fire and begin the finish touches and dial it in.
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