Hatred72

Hello all, I'm new to the site and have a few questions.

i have a 99 suburban that had a tired 5.7 vortec with another blown intake gasket wih 230,000 miles, instead of going with a rebuild or crate engine I decided to go with a 5.3 ls engine.

first I picked up a 2006 l59 5.3 with 36,000 miles complete lift out, and a 4l60e out of a 2005 chevy truck with 15,000 miles what i,m not sure of is do i need my old pcm and harness or can i use the ls modified harness. ive scanned over post after post but cannot find anything specific on my year truck. my suburban is an obs but is also a transitional year for the new body style. any help anyone can privide would help me alot.

The old engine and trans is out and i'm getting ready to install the new engine and trans if i could remove the old harness it would help but i'm not sure if any of the wires are needed for the abs/airbags or guages. thanks in advance.

tfi racing

iTrader: (2)

Easiest swap possible,you can modify the existing harness to work with the 5.3 and even use your existing 4L60E if you want,I would chuck that chevette based turd of a transmission and go with a 4L80E instead.Google "411 PCM swap" and you should get the answers you are looking for.

jdustin

I am doing a swap in a 99 suburban to a 5.3 does any one have any info on which harness to go with for the transmision? its a 4x4 and i am using a 5.3 engine and 4l60e trans mision and harness from the donor vehichle and allso using my computer from the suburban . what do i need to do to make the transmission and transfercase to work propperly?

GENIIIDude

I swapped in a LQ9 6.0 in my 98 K2500 Burb. I used the original 5.7 harness and just repinned it into the 0411 ecm, added the 6.0 injector pigtails (same color of wires), wired in the coils to the fuse block and ecm, and boom - running truck! The only issue I ran into was that the fuel gauge does not work through the 0411 ecm - so I just added a gauge on the pillar. Good luck...

GENIIIDude

The 5.7 Suburban computer (black with 4 plugs) will not run the 5.3 because it does not have the coil-on-cylinder drivers in it. You'll need the computer that came with your 5.3.

jdustin

yea that wont work, but thank you for the reply