2003 to 2008 5.3 vortec swap possible?

Harrison Fischer · November 1, 2019

I have a 2008 Silverado 1500 LT with the 5.3 vortec and it needs a new engine. Is it possible to put a 2003 5.3 Vortec engine in this truck or not?

Formulabruce · November 1, 2019

18 minutes ago, Harrison Fischer said:

I have a 2008 Silverado 1500 LT with the 5.3 vortec and it needs a new engine. Is it possible to put a 2003 5.3 Vortec engine in this truck or not?

You might get a better answer in the 1500 truck section. That said; the 03 is a drive by cable I believe, and the 08 is drive by wire. You would at least need to change the intake/induction system.

Mikebtte · November 1, 2019

the 2008 will have AFM and the 2003 will not. If looking for a replacement without AFM you could look for an engine out of an express van, it will not have AFM and will be the same serious of engine. If only looking to use the block you could make it work.

SierraHD17 · November 1, 2019

Simple answer is no. You will never make a Gen 3 engine work in a Gen IV platform without doing so much to the engine it's not worth installing. Find another Gen IV ( 07 GMT900 through 09 to avoid the VVT your 08 doesn't have that came along in 2010). Done.

sefiroxx · November 2, 2019

Drive by wire, transfer your throttle to the replacement.

Send the ecu out for programming for something like an 04 which was wire and pre AFM and VVT

CamGTP · November 2, 2019

7 minutes ago, sefiroxx said:

Drive by wire, transfer your throttle to the replacement.

Send the ecu out for programming for something like an 04 which was wire and pre AFM and VVT

No.

We are still talking two completely different generations of engines here.

The GEN 3 engine from 99-07 was both cable and drive by wire but now we get deep one why this swap is stupid and a waste of money. The GEN 3 engine is a 24x crank trigger where as the GEN 4 (07.5+) are 58x. The camshaft trigger is a 1x on the GEN 3 and 4x on the GEN 4.

The camshaft sensor on the front cover of the GEN 4 and not in the rear of the engine like the GEN 3. The knock sensors are in the valley under the intake of the GEN 3 and the GEN 4 has them bolted to the side of the block on each side just above the oil pan.

So to make this work it would involve tons of work with swapping parts over. Drilling and taping the block for the knock sensors. Having to take the crank to a machine shop to swap reluctors. Buying a new 3 bolt 4x cam gear and other stupid stuff that just costs more and more money.

At this point you could have bought the correct engine or just rebuilt/fixed the engine in the truck and been further ahead.

Last point, the 1999-2002 trucks use a P01 computer. 2003-2007's use a P59 computer. 2007.5+ use a E38 computer with the newer CAN-BUS systems. You can not program a newer computer to run an older generation calibration.

So yep, nope.

steven graham · October 6, 2022

Will a 2003 Chevy suburban 5.3 vortec fit in a 2004 Chevy Silverado with the same 5.3 but one of the e85 and the other ones not

CamGTP · October 6, 2022

It's all the same. The E85 stuff is just a sensor and programming, the long block itself will swap over no problems.

jaysin draco · October 30, 2023

I have a 08 Yukon XL SLT and it has the DOD 5.3, I found a 04 GMC 5.3 engine, with computer, can I swap them?

dsr611 · November 2, 2023

On 10/30/2023 at 12:54 PM, jaysin draco said:

I have a 08 Yukon XL SLT and it has the DOD 5.3, I found a 04 GMC 5.3 engine, with computer, can I swap them?

Guessing you didn't bother reading this or you would find your answer

On 11/1/2019 at 9:40 PM, CamGTP said:

No.

We are still talking two completely different generations of engines here.

The GEN 3 engine from 99-07 was both cable and drive by wire but now we get deep one why this swap is stupid and a waste of money. The GEN 3 engine is a 24x crank trigger where as the GEN 4 (07.5+) are 58x. The camshaft trigger is a 1x on the GEN 3 and 4x on the GEN 4.

The camshaft sensor on the front cover of the GEN 4 and not in the rear of the engine like the GEN 3. The knock sensors are in the valley under the intake of the GEN 3 and the GEN 4 has them bolted to the side of the block on each side just above the oil pan.

So to make this work it would involve tons of work with swapping parts over. Drilling and taping the block for the knock sensors. Having to take the crank to a machine shop to swap reluctors. Buying a new 3 bolt 4x cam gear and other stupid stuff that just costs more and more money.

At this point you could have bought the correct engine or just rebuilt/fixed the engine in the truck and been further ahead.

Last point, the 1999-2002 trucks use a P01 computer. 2003-2007's use a P59 computer. 2007.5+ use a E38 computer with the newer CAN-BUS systems. You can not program a newer computer to run an older generation calibration.

So yep, nope.

redvett · November 2, 2023

2003 is a gen 1 and 2008 is a gen 3 so no as it would require rewiring and custom programming stay with the same engine in your truck now for simplicity and no headaches, i would suggest a GM crate engine from GM.

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GM Performance crate engines are covered under the provisions of the GM Dealer Service Parts and Accessories Warranty for 24 months from the original sale or 50,000 miles, whichever comes first.