[Alex0032]

Hey guys, I’m new here and looking for some advice. I have a 2004 Silverado 2WD with a 4.3 vortec in it. Looking to swap it out with a 4.8 or 5.3. I read in other forums that it can be done with a 5.7, but no information if it’s applicable with my vehicle. Any advice as to what needs to be changed within the swap and what’s applicable?

 

[JTward1]

5.3 liter is a 5.3 V8, But's just restyle V8 vortec. It's a 5300 Vortex 5300 V8 It was a different LS series of engines under the LS badge, but it is one of the LS series, like LS1, LS 1, 2, and 3 were all alumen engines and LS 4, 5 were cast iron blocks, were truck engines after that all the other 7-8-9 engines wound up in Corvettes Camroe and police cars.

Personally I'd put a great 5.7 liter. Nothing beats Horsepower.

 

[xPosTech]

Go route around this site. You might need to replace the PCM and fuel system. This site has everything you need to know.

https://www.lsenginediy.com

Ted

 

[squatchy]

5.7 isn’t as good as a 5.3, don’t waste your time with that

 

[Alex0032]

Thanks guys. I decided to go with the 5.3 engine. I’m on the hunt for one around my area.

 

[JTward1]

5.7 isn’t as good as a 5.3, don’t waste your time with that

I was trying to simulate the fact that both are V8. Personally I'd go for a GMPP 5.3 liter V8. Maybe it's me, but there are some really good deals out there ? I bought a 5.7 back in 2012 from Jasper. It came with 3 warranty / 100.000. How can you wrong with that $2100.00 Runs like watch, smooth as silk. But to each his own.

 

[RayVoy]

Just to toss my thoughts into the mix, going from a V6 (old school) to a V8 (new school) could be a wiring nightmare.

The V6 is a kin to the old 5.7 V8 not to the LS based 5.3

The wiring harness for a 5.3 would be very complex compared to the old school V6. For example do you still have a distributor?

 

[JTward1]

Just to toss my thoughts into the mix, going from a V6 (old school) to a V8 (new school) could be a wiring nightmare.

The V6 is a kin to the old 5.7 V8 not to the LS based 5.3

The wiring harness for a 5.3 would be very complex compared to the old school V6. For example do you still have a distributor?

Great Point Ray, but I wonder if you could buy the front half of wiring harness . From the firewall forward ? But then it would have negative results.

 

[RayVoy]

Great Point Ray, but I wonder if you could buy the front half of wiring harness . From the firewall forward ? But then it would have negative results.

I don't know JT, I'm just thinking there would be some missing wires

 

[xPosTech]

Yes a donor engine harness and PCM is necessary. Whether stock or cut down is something Alex will have to decide. The site I refered him to covers all the things he requires. It is all things LS.

Ted

 

[JTward1]

Yeah Ted, It would be better off getting from a wreck from a 5.3 truck and clean it up and checking for any cracks in the wires.