2000 Silverado 4.3 swap to a 5.3 from 2004 donor Silverado

[joeboston]

I am replacing my tired 4.3 V6 in my 2000 Silverado (Manual Trans) with a 5.3 from a 2004 Silverado (Auto). I am getting the complete wiring harness and computer from the donor Silverado.

I am trying to determine which computer to use. The original from the 4.3 or the newer one from the 5.3. Either way I will need to update the computer to account for the new trans or engine (Depending one which one I use).

I am open to suggestions and how to go about importing the new code.

I would like to keep the original 4.3 computer since I have already used my license with it. Just not sure I would be able to use it with the 5.3 or not and import the required settings.

Thanks
Joe

[Taz]

The 2000 4.3L V6 in your Silverado was controlled by a "Black Box" Vortec PCM - which is not compatible with the 5.3L engine you wish to install.

You will need a 512 Kb LS1-B PCM (not the 1 Mb LS1-B PCM that may have came with the 2004 5.3L donor engine). Then wire the truck per a 2000 Silverado with a 5.3L.

You can reuse the 5 speed manual transmission from your existing truck - but you will need the proper flywheel & clutch assembly for a 5.3L engine.

You can also convert the truck to an automatic - the choice is yours.


Regards,
Taz

[joeboston]

Thanks for the help Taz.

If I went with a 2000 or 2001 5.3 out of a Silverado. Would this make a difference which PCM I would use.

This guy has a large selection of engines to chose from: http://stores.ebay.com/bowautoparts?_trksid=p4340.l2563

I found this PCM on ebay, do you think this would work with the 2004 5.3 setup you suggested?
http://www.ebay.com/itm/Silverado-1500-2000-00-Engine-Computer-ECM-PCM-9354896-Programmed-your-VIN-/220909995591?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item336f430647

Thanks
Joe

[Taz]

If you were thinking of doing this conversion yourself, I would highly recommend purchasing the OEM service manual set from Helm Inc. This conversion is very different than swapping a Gen III into an older vehicle or kit car. Many of the considerations in what components to use relate to the TRUCK not the engine.

Any Gen III engine could be controlled with an LS1-B PCM (512Kb or 1Mb) in a custom application. Your truck has a BCM, EBCM, SIR (airbag), and IPC that require a compatible PCM and OS. The A/C and Cruise systems are different between 1999-2002 and 2003-2007 (classic) Sierra / Silverado. Most 1999-2002 Sierra / Silverado were DBC, while all 2003-2007 (classic) Sierra / Silverado were DBW.

I would recommend a lot more research into this project prior to purchasing any components.


Regards,
Taz

[ScarabEpic22]

Definitely use a 512kb LS1B PCM and NOT anything else for the PCM. Repin the harness/use an 00-02 5.3L harness. To retain all the features like cruise, AC, fans, etc you HAVE to pair the proper PCM with the proper OS. Don't fret about the trans, thats actually the easiest part of the whole deal so far. Do a segment swap and you're off.