03 silverado 4.3 to 5.3

[jsisk]

Hey guys ive been searching my ass off on here and need some help.I bought a 03 silverado with 4.3 5 speed with 76,000 miles im wanting to throw in a 5.3 i know i need a 4.8 clutch and fly wheel but what year 5.3 and harness bc i dont have drive by wire i have a throttle cable and i found a good deal on a complete 01 5.3 with harness and any part i need but i dont wanna buy it if it wont work,im tryin to get all my stuff together before i start so im not searching for stuff i appreciate ur help and any tips would be great

[TXSZ66AVLANCHE]

So easy a caveman could do it. You need a engine harness from a 99-02 truck that has a cable throttle body, it don't matter if its a automatic truck. The speed sensor connector for the transmission is what you really need. Un bolt the 6cyl harness from the fuse box, connect the v8 harness, custom tune for the pcm. There is a few other steps but its actually pretty simple.

[blacstar]

Hey guys ive been searching my ass off on here and need some help.I bought a 03 silverado with 4.3 5 speed with 76,000 miles im wanting to throw in a 5.3 i know i need a 4.8 clutch and fly wheel but what year 5.3 and harness bc i dont have drive by wire i have a throttle cable and i found a good deal on a complete 01 5.3 with harness and any part i need but i dont wanna buy it if it wont work,im tryin to get all my stuff together before i start so im not searching for stuff i appreciate ur help and any tips would be great

keep the 4.3 harness to splice in if u want reverse lights. An LS flywheel-disc-pp, V8 engine mounts and frame mounts, both a/c lines and compressor if you dont have one, keep the fuel lines on the truck. ask questions, im sure im forgetting some things

[jsisk]

keep the 4.3 harness to splice in if u want reverse lights. An LS flywheel-disc-pp, V8 engine mounts and frame mounts, both a/c lines and compressor if you dont have one, keep the fuel lines on the truck. ask questions, im sure im forgetting some things

do i need ac lines from the 5.3 and if so which ones the ones that run acroos the engine or the ones that go in the box the 2 aluminium ones and thanks guys for ur help

[Frenchy]

So easy a caveman could do it. You need a engine harness from a 99-02 truck that has a cable throttle body, it don't matter if its a automatic truck. The speed sensor connector for the transmission is what you really need. Un bolt the 6cyl harness from the fuse box, connect the v8 harness, custom tune for the pcm. There is a few other steps but its actually pretty simple.

Uhm. No. You're wrong.

You need to convert to DBW. It's a not a big deal at all, the truck is already setup for it and the pedal and TAC module will bolt right in. You need an 03-05 harness and pcm. You need the entire A/C setup, compressor, compressor bracket and any lines that attach to the compressor

[TXSZ66AVLANCHE]

You don't need to convert to drive by wire, you can....but only if that's what you want to do. Since the v6 truck is already a cable throttle its just one less step.

[jsisk]

Uhm. No. You're wrong.

You need to convert to DBW. It's a not a big deal at all, the truck is already setup for it and the pedal and TAC module will bolt right in. You need an 03-05 harness and pcm. You need the entire A/C setup, compressor, compressor bracket and any lines that attach to the compressor

why would i want to convert to dbw if my truck doesnt have it and the truck im getting the 5.3 from doesnt have it?

[blacstar]

why would i want to convert to dbw if my truck doesnt have it and the truck im getting the 5.3 from doesnt have it?

the harness/fuse box pins are different, its alot easier to just do what Frenchy said! save u time and stress

[Frenchy]

You don't need to convert to drive by wire, you can....but only if that's what you want to do. Since the v6 truck is already a cable throttle its just one less step.

Yes. You do. I have done the swap. Have you? The 99-02 engine harness and PCM will NOT work with the 03+ BCM. Without serious, re-engineering.

why would i want to convert to dbw if my truck doesnt have it and the truck im getting the 5.3 from doesnt have it?

You want your truck to run without countless headaches right? My truck is a swap. There's other guys who have tried keeping DBC in the newer trucks, guess what? Those trucks are now DBW. There was a ton of changes between 02 and 03 electrically. Go DBW. or don't listen, do it ass backwards, go about it, have lots of trouble and go DBW anyway.

[jsisk]

Yes. You do. I have done the swap. Have you? The 99-02 engine harness and PCM will NOT work with the 03+ BCM. Without serious, re-engineering.



You want your truck to run without countless headaches right? My truck is a swap. There's other guys who have tried keeping DBC in the newer trucks, guess what? Those trucks are now DBW. There was a ton of changes between 02 and 03 electrically. Go DBW. or don't listen, do it ass backwards, go about it, have lots of trouble and go DBW anyway.

Im not understanding at all so if my truck is not dbw and the engine im gettin is not dbw i still need to convert it?If so could i just by a 03 5.3 and the harness work with out doing dbw?