Official NBS V6 to GENIII V8 swap Guide
02-09-2021, 10:06 PM
#421
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4.3 swap 6.0
I have a 04 chevy silverado had 4.3 swap to 6.0 came out of a 2000 chevy silverado 2500 and had got harness and ecm from the 2000 truck had ran into issues with the harness for the truck side now with just turning key on to the frist trun it cranks over just with the key in the frist trun so was wondering if anyone can help me out please thanks I see you did the swap did you have to change any wires in the fuse box and under the fuse box ?
02-10-2021, 11:02 AM
#422
I have a 04 chevy silverado had 4.3 swap to 6.0 came out of a 2000 chevy silverado 2500 and had got harness and ecm from the 2000 truck had ran into issues with the harness for the truck side now with just turning key on to the frist trun it cranks over just with the key in the frist trun so was wondering if anyone can help me out please thanks I see you did the swap did you have to change any wires in the fuse box and under the fuse box ?
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Dureno1 (03-18-2021)
03-21-2021, 02:24 PM
#423
Electrical trouble on v6-v8 swap NBS silverado. rf
i need help in my swap, i have an 03 that i bought,it was originally a v6 but when i bought it, it had a 5.3 in it, it did not run, it came with an electric pedal harness setup, i removed it and used a cable drive harness. where im running into issues is at the fuze box part of things,if i set it up with a 99-02 fuse box, i can get the engine to run but no power to the inside of the cab, because of the power connectors not plugging into the fuse box, but when i hook it up with a 03+ fuse box, i can get power to the inside of the cab, but i cant get the engine to run.
maybe i need a new harness?
maybe i need to repin my harness to fit the 03+ fuse box?
maybe i should go back to the electric pedal setup and see what it does?
im serioulsy lost and need help, as im starting dual enrollment classes in the fall and will travel from my high school to my community college DAILY!!!
any help is appreciated, i am 16 years old and doing it all on my own, my knowledge is not so profound relating to Ls's but i simply want to have my truck running, and be able to dagnose it, proper working gauges and everything on the inside,.
i know it might be confusing, but please reach out as i could give you a call, to better explain thanks to all you. Have a blessed Sunday.!!
maybe i need a new harness?
maybe i need to repin my harness to fit the 03+ fuse box?
maybe i should go back to the electric pedal setup and see what it does?
im serioulsy lost and need help, as im starting dual enrollment classes in the fall and will travel from my high school to my community college DAILY!!!
any help is appreciated, i am 16 years old and doing it all on my own, my knowledge is not so profound relating to Ls's but i simply want to have my truck running, and be able to dagnose it, proper working gauges and everything on the inside,.
i know it might be confusing, but please reach out as i could give you a call, to better explain thanks to all you. Have a blessed Sunday.!!
03-22-2021, 01:02 AM
#424
100% Redneck
If you go with the drive by wire pedal and TAC module, you will of course need a drive by wire throttle body. You've found out you can't use a 99-02 engine wiring harness on a 2003+ truck. What computer do you have... does it say "blue red" or "blue green" on the computer housing?
You can run a cable throttle body on a 03+ truck using an engine wiring harness and computer from a 2003+ Chevy Express or GMC Savana van. The vans still had cable throttles and the wiring harness has the IAC (idle air control) sensor connection plug along with IAC support in the computer. The 03+ truck harness does not have the IAC sensor plug needed for a cable throttle body and in most cases the computer does not have IAC support (IAC driver) like the vans do.
Bottom line is:
For cable you need the 03+ van engine harness and computer.
For drive by wire you need a 03+ truck blue/green engine harness, blue/green computer, drive by wire pedal & TAC module, and a drive by wire throttle body.
https://lt1swap.com/cable_conversion.htm
You can run a cable throttle body on a 03+ truck using an engine wiring harness and computer from a 2003+ Chevy Express or GMC Savana van. The vans still had cable throttles and the wiring harness has the IAC (idle air control) sensor connection plug along with IAC support in the computer. The 03+ truck harness does not have the IAC sensor plug needed for a cable throttle body and in most cases the computer does not have IAC support (IAC driver) like the vans do.
Bottom line is:
For cable you need the 03+ van engine harness and computer.
For drive by wire you need a 03+ truck blue/green engine harness, blue/green computer, drive by wire pedal & TAC module, and a drive by wire throttle body.
https://lt1swap.com/cable_conversion.htm
04-03-2021, 11:45 AM
#425
Hey so i guess a more in depth explanation would be better in order for me to get better help.
the truck is an 03 silverado with a 5.3 in it, the 5.3 came out of a 99-02 truck. i have multiple harnesses, along with multiple computers. i know for a fact that ti have a complete DBW harness( harness module, pedal, and TB). i also know i have at least one DBC harness.Ultimately my question is this, HOW DO I COMPLETE MY SWAP? My father bought a junked 99-02 truck complete, he told me to do a complete dash, harness and whatever i needed swap, from the 99-02 into muy 03. i think thats way too much work for a simple solution.
do i use a DBW setup?,if so, i would need someone to tune one of the many green/blue cpus i have correct? and if i do go in that direction, do i use the same year fuze box?
if i want to stick with the DBC setup, what harness, and fuze box do i need?
i guess i should also mention i have a neighbor with a junked 04 silverado DBW, i offered him 150 for the harness, pedal, and module, and computer, he accepted, but i have yet to pay him due to not wanting to waste money if i can simply use the one i already have.
ANY HELP IS GREATLY APPRECIATED!!!'
the truck is an 03 silverado with a 5.3 in it, the 5.3 came out of a 99-02 truck. i have multiple harnesses, along with multiple computers. i know for a fact that ti have a complete DBW harness( harness module, pedal, and TB). i also know i have at least one DBC harness.Ultimately my question is this, HOW DO I COMPLETE MY SWAP? My father bought a junked 99-02 truck complete, he told me to do a complete dash, harness and whatever i needed swap, from the 99-02 into muy 03. i think thats way too much work for a simple solution.
do i use a DBW setup?,if so, i would need someone to tune one of the many green/blue cpus i have correct? and if i do go in that direction, do i use the same year fuze box?
if i want to stick with the DBC setup, what harness, and fuze box do i need?
i guess i should also mention i have a neighbor with a junked 04 silverado DBW, i offered him 150 for the harness, pedal, and module, and computer, he accepted, but i have yet to pay him due to not wanting to waste money if i can simply use the one i already have.
ANY HELP IS GREATLY APPRECIATED!!!'
03-11-2022, 09:31 PM
#426
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Bringing this thread back to life.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
03-11-2022, 10:41 PM
#427
Bringing this thread back to life.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
https://www.ls1truck.com/forums/lsx-...onversion.html is one that comes to mind.
otherwise, a 350 is a super-simple upgrade for much less time & money
03-13-2022, 10:58 PM
#428
Bringing this thread back to life.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
I recently bought a 1998 C1500 2WD 4.3L V6 with over 208K miles on the clock with the intention of doing an engine swap to either 5.3L or 6.0L and upgrading to a 4L80 tranny. I might eventually add a Turbo down the road, but my focus is on the swap first. I'm currently trying to gather a parts list to slowly get this project going.
03-31-2022, 10:59 PM
#429
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NBS V6 to V8 Swap
So basically you’re tired of going slow and want some power and obviously you want to swap out that old 4.3 for that massive V8
so let’s get to it. There are some other threads out there but they aren’t really informative because most people have a shop do the swap unlike me who did the swap myself with a few friends.
What do I need?
You need the engine of course, the motor needs to be turn-key.
turn-key means 100% ready to bolt in and fire up. It needs to look like this
Attachment 138390
Attachment 138391
It needs the wiring harness from a V8 Silverado, if you have a 99-02, get that harness if your motor is 03+ be sure to get a harness for an 03+ reason being the 99-02 models have a drive by cable throttle body and the 03+ models has the electronic throttle body.
Manifolds: the hell with manifolds get you some long tube headers and custom exhaust.
Pacesetters are great for the price. You can reuse your stock manifold bolts and gaskets off the v8 motor if your new motor came with them.
PCM- AKA the computer- The V6 PCM is the exact same externally as the V8 PCM the only difference is the tune or program that is written to the PCM. So you will need to have your V6 PCM reflashed and tuned with the V8 parameters. I would recommend Nelson Performance. http://www.nelsonperformance.com
Allen will send you a PCM tuned for your new motor and mods in which you have installed. The tuned PCM will also be tuned for the V6 Vin # so everything will fire up on the first try if everything is hooked up correctly. Once you receive the new PCM simply send Nelson Performance your stock V6 PCM. Nelson Performance is not the only option, there are some other options such as custom DYNO tuning or other mail order tuners. Just be sure to ask whoever does the tuning if they can indeed reflash the V6 PCM with the V8 parameters and V6 vin.
Transmission- The V6 transmission will bolt up but it will live a short life behind the new powerplant. I would recommend purchasing a built unit from a reputable Transmission shop such as FLT (Finish Line Transmissions) Finish Line Transmissions | Performance Transmissions | Torque Converters | Transmission Parts | Transmission Service
FLT builds flawless units everytime and they dyno test them before shipment. Chuck or Vince can recommend a specific model for your needs.
Note: the stock V8 unit will break just as fast so get a good built unit that will suit your needs.
Torque Converter:
A stock V8 converter will work but the whole purpose of this swap is for power right?
A torque converter alone can knock off a ½ second off of your ET.
Vigilante and Yank build good stalls, They can recommend a stall speed for your application and mods.
Flexplate- You will need a 4l60e flexplate from a V8 motor, a stock one should work fine.
Note: If you purchased a 6.0 and it has a flexplate on it already it probably will not work because the engine was most likely mated to a 4l80e transmission.
Fan shroud: you will need a v8 fan shroud if you plan on using the clutch fan, BTW now is a good time to upgrade to E-FANS!!! If you do upgrade no shroud will be necessary.
Motor mounts: unfortunately the stock mounts will not work. You will need to purchase 99-03 ½ ton frame mounts and engine mounts, you can get these at your local chevy dealer or find them from a salvage yard.
Hoses: you will need 99-03 radiator hoses- upper and lower, AC hoses, Heater hoses,
you will also need a nipple that connects to the back of the intake manifold that provides vacuum for your brake booster, the 6.0 engines power breaks use their power steering pump. you can get this from the dealer or off a 4.8,5.3 intake manifold.
Radiator: yes your stock v6 radiator will work, the only difference between the 28” v6 radiator and the 28” v8 one is one small connector that returns coolant back to the radiator from the throttle body, search TB bypass for more info. Simply install a T on the hose coming from the radiator reservoir that runs to the radiator and connect the line from the Throttle body or block (if you bypassed) to the T fitting. Be sure to use hose clamps to insure no leaks.
Air Intake: the air intake setup on the V8 engines are completely different than the v6 setup, you can purchase a stock unit or replace with an aftermarket setup. FYI you can also do a search on the board that will inform you of what you will need and where to buy specific parts to build your on Cold air setup that will compare to the best aftermarket ones.
Note: the stock box will work you just need the tube.
The stock MAF (mass air flow sensor will work as well)
Fuel Lines: The stock fuel lines will not work with the new motor, you will need
2 EAR-165056ERL -6 - 5/16 AN to tubing connectors Male end
2 EAR-165006ERL -6 - 3/8 AN to tubing connectors Male end
2 RUS-658490 1 ft sections of pre assembled 5/16 Steel braided hose with female ends
Simply attach one 5/16 to -6 tubing connector to the fuel rail on the intake manifold
Then attach the 3/8 to -6 tubing connector to the return line on the fuel rail on the manifold the above PN#’s are from Summit Racing
Cut the fuel “tubing” about 6 inches below the firewall and follow the same steps as above. Now attach the hoses to the fittings which are now on the tubing. MAKE SURE the fittings are on snug! Now when the time comes to hook up the lines simply screw on the lines to the manifold.
Note: be sure to label the lines, Fuel and return. Fuel being the larger line and the return the smaller in diameter.
Oil cooler: most 6.0’s come with a oil cooler stock from the factory, this is not needed so you can buy the block off plate that comes on the v8 engines. The oil cooler lines will connect right above the oil filter on the block. You can get this part from your local dealer for a few bucks, be sure to get the gasket as well.
Well that’s it, other than the above you just need to know how to pull a motor and how to put one back in! which can be found here. https://www.performancetrucks.net/fo...d.php?t=363112
Good luck and if you have any questions or comments about this thread Post up!
Attachment 138392
Attachment 138393
Attachment 138394
Attachment 138395
Attachment 138396
So basically you’re tired of going slow and want some power and obviously you want to swap out that old 4.3 for that massive V8
so let’s get to it. There are some other threads out there but they aren’t really informative because most people have a shop do the swap unlike me who did the swap myself with a few friends.What do I need?
You need the engine of course, the motor needs to be turn-key.
turn-key means 100% ready to bolt in and fire up. It needs to look like this
Attachment 138390
Attachment 138391
It needs the wiring harness from a V8 Silverado, if you have a 99-02, get that harness if your motor is 03+ be sure to get a harness for an 03+ reason being the 99-02 models have a drive by cable throttle body and the 03+ models has the electronic throttle body.
Manifolds: the hell with manifolds get you some long tube headers and custom exhaust.
Pacesetters are great for the price. You can reuse your stock manifold bolts and gaskets off the v8 motor if your new motor came with them.
PCM- AKA the computer- The V6 PCM is the exact same externally as the V8 PCM the only difference is the tune or program that is written to the PCM. So you will need to have your V6 PCM reflashed and tuned with the V8 parameters. I would recommend Nelson Performance. http://www.nelsonperformance.com
Allen will send you a PCM tuned for your new motor and mods in which you have installed. The tuned PCM will also be tuned for the V6 Vin # so everything will fire up on the first try if everything is hooked up correctly. Once you receive the new PCM simply send Nelson Performance your stock V6 PCM. Nelson Performance is not the only option, there are some other options such as custom DYNO tuning or other mail order tuners. Just be sure to ask whoever does the tuning if they can indeed reflash the V6 PCM with the V8 parameters and V6 vin.
Transmission- The V6 transmission will bolt up but it will live a short life behind the new powerplant. I would recommend purchasing a built unit from a reputable Transmission shop such as FLT (Finish Line Transmissions) Finish Line Transmissions | Performance Transmissions | Torque Converters | Transmission Parts | Transmission Service
FLT builds flawless units everytime and they dyno test them before shipment. Chuck or Vince can recommend a specific model for your needs.
Note: the stock V8 unit will break just as fast so get a good built unit that will suit your needs.
Torque Converter:
A stock V8 converter will work but the whole purpose of this swap is for power right?
A torque converter alone can knock off a ½ second off of your ET.
Vigilante and Yank build good stalls, They can recommend a stall speed for your application and mods.
Flexplate- You will need a 4l60e flexplate from a V8 motor, a stock one should work fine.
Note: If you purchased a 6.0 and it has a flexplate on it already it probably will not work because the engine was most likely mated to a 4l80e transmission.
Fan shroud: you will need a v8 fan shroud if you plan on using the clutch fan, BTW now is a good time to upgrade to E-FANS!!! If you do upgrade no shroud will be necessary.
Motor mounts: unfortunately the stock mounts will not work. You will need to purchase 99-03 ½ ton frame mounts and engine mounts, you can get these at your local chevy dealer or find them from a salvage yard.
Hoses: you will need 99-03 radiator hoses- upper and lower, AC hoses, Heater hoses,
you will also need a nipple that connects to the back of the intake manifold that provides vacuum for your brake booster, the 6.0 engines power breaks use their power steering pump. you can get this from the dealer or off a 4.8,5.3 intake manifold.
Radiator: yes your stock v6 radiator will work, the only difference between the 28” v6 radiator and the 28” v8 one is one small connector that returns coolant back to the radiator from the throttle body, search TB bypass for more info. Simply install a T on the hose coming from the radiator reservoir that runs to the radiator and connect the line from the Throttle body or block (if you bypassed) to the T fitting. Be sure to use hose clamps to insure no leaks.
Air Intake: the air intake setup on the V8 engines are completely different than the v6 setup, you can purchase a stock unit or replace with an aftermarket setup. FYI you can also do a search on the board that will inform you of what you will need and where to buy specific parts to build your on Cold air setup that will compare to the best aftermarket ones.
Note: the stock box will work you just need the tube.
The stock MAF (mass air flow sensor will work as well)
Fuel Lines: The stock fuel lines will not work with the new motor, you will need
2 EAR-165056ERL -6 - 5/16 AN to tubing connectors Male end
2 EAR-165006ERL -6 - 3/8 AN to tubing connectors Male end
2 RUS-658490 1 ft sections of pre assembled 5/16 Steel braided hose with female ends
Simply attach one 5/16 to -6 tubing connector to the fuel rail on the intake manifold
Then attach the 3/8 to -6 tubing connector to the return line on the fuel rail on the manifold the above PN#’s are from Summit Racing
Cut the fuel “tubing” about 6 inches below the firewall and follow the same steps as above. Now attach the hoses to the fittings which are now on the tubing. MAKE SURE the fittings are on snug! Now when the time comes to hook up the lines simply screw on the lines to the manifold.
Note: be sure to label the lines, Fuel and return. Fuel being the larger line and the return the smaller in diameter.
Oil cooler: most 6.0’s come with a oil cooler stock from the factory, this is not needed so you can buy the block off plate that comes on the v8 engines. The oil cooler lines will connect right above the oil filter on the block. You can get this part from your local dealer for a few bucks, be sure to get the gasket as well.
Well that’s it, other than the above you just need to know how to pull a motor and how to put one back in! which can be found here. https://www.performancetrucks.net/fo...d.php?t=363112
Good luck and if you have any questions or comments about this thread Post up!
Attachment 138392
Attachment 138393
Attachment 138394
Attachment 138395
Attachment 138396
https://lt1swap.com/2000harness.htm
This site also has incredible information for identifying sensors/harness types etc
06-17-2022, 07:44 PM
#430
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Can you elaborate on swapping over the purple clutch safety switch wire in the fuse box? I grabbed an auto harness for my swap. 2000 4.3 to 2001 5.3 DBW with nv3500. Harness came off a 2001 Silverado Z71 with 4L60 4x4.