headlayoutman1

I have a 2006 WT long box with the 4.3 v6 engine and 4L60e trans 2 whl drive . It has cruise control , air conditoning , electric cooling fans , and I installed a 4:10 rear axle ratio . It does not have VATS .

I need more power for towing .

I want to swap in a 5.3 or 6.0 .

I am pretty much set with everything that I need for the swap , Because I will get a complete running compatible LS 3 donor truck for the engine and wiring harness .

My question is which route to go as far as the ECM , should I use the v6 ECM and just reflash to v8 , or use the donor trucks ECM with the VATS deleted , ? or is there another way to go with this ?

I just want a stock v8 tune , to have a daily driver capable of towing .

madmann26

iTrader: (7)

Your best bet is to stick to a gen3 5.3/6.0. The ls3 uses a 58x reluctor on the crank and you’ll need a Lingenfelter conversion box to run it.

Then you’ll have to address the knock sensor and cam sensor harness issues.

Then you’ll have to address the gauges not working.

FFDP

iTrader: (2)

I have a feeling that "3" was a mistype as he was hinting at the compatible swap part.

You'd want to use the V8 computer as that would be faster to get you going with a tune. The 4.3 computer would need to be flashed with a V8 operating system to function.

Being that this truck is a 2006, whatever you find would want to be a DBW V8 truck so all your dash stuff works without extra things being done. I assume you know that all the wiring for things like the pedal assembly and tac module will have to be brought over.

headlayoutman1

Thanks , I am getting a 2005 or 2006 donor truck for the gen 3 engine and wiring harness ,
I just dont know which ecm to use ? The donor trucks ecm ? , or the 4.3 ecm reflashed to gen 3 ?

headlayoutman1

yes I know all the other things , as far as mounts and drive by wire , tach module , I just am unsure what has to be done with the ecm , will it have to be reset for the different rear axle ratio ?, will it t recognize the electric cooling fans ? Does it matter if the doner is 4 wheel drive and the swapped truck is 2 wheel drive ?

FFDP

iTrader: (2)

The computer will have to be tune no matter what.

With how much that could be different between the trucks like 2WD and 4WD plus the fact that you installed 4.10's, it may end up costing you a couple bucks to complete this unless you know a few people.

You could take the V8 donor computer and have it flashed with a matching calibration. Lets say for example you buy a 2006 5.3 donor truck. The computer could be flashed with a GM tool to a 2006 5.3 2WD calibration (this is if the truck was a stock 4x4). Then with an after market tuner like HP Tuners the computer could be unlocked, the VATS disabled and then the gear ratio could be changed to 4.10's in the tune file to make the transmission shift work.

Again that's just an example of what could have to happen to make it seamless.

headlayoutman1

so in order to tune the ecm , provide the person doing the tune what other information ? the engine is 2005 L33 , 4l60E , 2 wheel drive , 4.10 ratio + tire size , no vats on truck , vin of truck , year of truck , what else ?

FFDP

iTrader: (2)

If the computer needed to be flashed with GM tool prior to a custom tune, then you'd need to have a proper VIN number to flash the computer too. The VIN wouldn't need to match the VIN on the truck it just needs to be a VIN that would would be for a calibration you want.


If something like that doesn't need to happen then the tuner really doesn't need much of anything. They would just hook up to the truck, read the file, license it and make the changes needed. Like deleting VATS and changing the rear gear ratio to make the transmission happy.

AngryBear

Get the PCM from the donor vehicle. You’ll still have to disable VATS on the donor PCM. I’m just finishing up a similar swap myself. 05 Silverado went from a 4.3 to a 5.3. Are you looking to tune it yourself? Send it out? Because that changes things a little.

headlayoutman1

I will probably send the ECM to Nelson Performance for the tune .