Official NBS V6 to GENIII V8 swap Guide
07-18-2015, 04:08 AM
#121
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08-13-2015, 10:47 AM
#122
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There is one thing I do not understand with this swap - the OP says to get the V8 wiring harness - which will plug into your flashed V6 (now V8) PCM. How do the guages work in the truck if you are not using the stock harness?
I would think you would have to take certain wires from the trucks original wiring and splice those into the new V8 wiring harness connector... This wasn't addressed at all -- am I missing something? I just don't see how the guages work if you aren't connecting them to anything on the new V8 harness
I would think you would have to take certain wires from the trucks original wiring and splice those into the new V8 wiring harness connector... This wasn't addressed at all -- am I missing something? I just don't see how the guages work if you aren't connecting them to anything on the new V8 harness
08-13-2015, 11:11 AM
#124
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If you throw a "turn key" harness/motor into a truck, yeah it will crank up and run - but none of the features that were originally in the vehicle will work that I listed above.
I may be missing something as far as "turn key" is defined.. When I think "turn key" I think of a standalone harness that will run the engine and do nothing more. I'm starting to think the 'turn key' harness, in this case, also includes connectors that connect to the truck's harness for guages/obd/etc.
It's pretty rare to find a harness w/ everything intact like that - usually shops/yards cut everything that is not going straight to the engine
Last edited by TXjeepTJ; 08-13-2015 at 11:18 AM.
08-13-2015, 11:18 AM
#125
The OP never addressed connecting the guages (or their data signal lines) to the PCM - That's what I'm confused on. There are numerous wires that go from the PCM connectors into the truck's 'body' such as the guages, cruise control (if DBW), brake signal for TCC, etc.
If you throw a "turn key" motor into a truck, yeah it will crank up and run - but none of the features that were originally in the vehicle will work that I listed above.
I may be missing something as far as "turn key" is defined.. When I think "turn key" I think of a standalone harness that will run the engine and do nothing more. I'm starting to think the 'turn key' harness, in this case, also includes connectors that connect to the truck's harness for guages/obd/etc.
It's pretty rare to find a harness w/ everything intact like that - usually shops/yards cut everything that is not going straight to the engine
If you throw a "turn key" motor into a truck, yeah it will crank up and run - but none of the features that were originally in the vehicle will work that I listed above.
I may be missing something as far as "turn key" is defined.. When I think "turn key" I think of a standalone harness that will run the engine and do nothing more. I'm starting to think the 'turn key' harness, in this case, also includes connectors that connect to the truck's harness for guages/obd/etc.
It's pretty rare to find a harness w/ everything intact like that - usually shops/yards cut everything that is not going straight to the engine
Again,the factory engine harness in these trucks plug right in to the Fuse box. Reprogramming the pcm is all that is needed for the signals to reach the gauges.
You do not have to change any other wiring.
There for it is a turn key swap.
The rest of the internal component like the gauges, wiring, control modules and so on are the same and don't distinguish between V8-V6.
08-22-2015, 08:20 PM
#127
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I have another question
regarding adapting the fuel lines - is the fuel connection on the V6 motor 3/8"? I believe all you are doing is extending the current fuel line -as the v6 and v8 use the same 3/8" fitting.
Is this right? or is the V6 fuel line connection at the fuel rail a different size?
My friends 4.3L looks like it is a returnless fuel system (2006 silverado). I just want to make sure I get him to get the right parts, as it is his daily driver, so we can't run into any problems when we start the swap! Thanks!
EDIT: if anyone is wondering about this - the V6 fuel rail is 3/8". All you are doing is extending the stock fuel line (though, looking at it right now - it looks like the stock port will reach the V8 intake fuel rail, but I will post back up confirming this)
regarding adapting the fuel lines - is the fuel connection on the V6 motor 3/8"? I believe all you are doing is extending the current fuel line -as the v6 and v8 use the same 3/8" fitting.
Is this right? or is the V6 fuel line connection at the fuel rail a different size?
My friends 4.3L looks like it is a returnless fuel system (2006 silverado). I just want to make sure I get him to get the right parts, as it is his daily driver, so we can't run into any problems when we start the swap! Thanks!
EDIT: if anyone is wondering about this - the V6 fuel rail is 3/8". All you are doing is extending the stock fuel line (though, looking at it right now - it looks like the stock port will reach the V8 intake fuel rail, but I will post back up confirming this)
Last edited by TXjeepTJ; 09-01-2015 at 09:20 AM.
09-01-2015, 09:19 AM
#128
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Is the OBD port ran through the fuse box also? The complete uncut wiring harness I got does not have ODB w/ it... I don't see any cut connections - hoping this is something routed through the fuse box
09-06-2015, 11:39 AM
#129
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New to the forum but I just bought a 02 Sierra RCSB 4.3 4x4 nv3500 and I want to put the vortec 4.8 so I plan on finding a 02-03 4.8 DBC so as far as I can tell if I have a turn key engine and harness and the flywheel spacer everything should bolt up as long as the 4.8 has both sides of the mounts all acc. Will bolt up P/S, a/c, alt and the radiator should work get my comp re flashed for v8 parameters and idk about the fuel setup possibly extend the lines and get the v8 rad hoses. Is there anything I am missing
09-09-2015, 06:47 PM
#130
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Quick question and I think I'll have all this figured out. I have an 01 4.3. If I get a complete take out from a 2004 6.0 with harness and computer, do I need to change anything because of the drive by wire Tb?