2017 L83 into 1997

[RaymondNoodle]

Newbie here.

looking to gather some information on putting a 2017 L83 and 8l90 into a 1997 ext cab

I have found a little bit of information on the swap but I am still trying to gather more.

we have already purchased the Engine and transmission

my main concern is the wiring. I’d like a little more insight on what needs to stay and go on the factory harness.

Or If there is anyone that sells a direct plug and play set up I’d be willing to purchase one.

 

[Schurkey]

I’d like a little more insight on what needs to stay and go on the factory harness.

First Guess: It'll be easier to transfer the entire engine-transmission-computer and wire harness from the donor vehicle than to "fix" the existing harness. You're gonna need the original engine and trans computer(s); you might as well just grab the whole freakin' harness.

EDIT: Should say "You're gonna need the DONOR VEHICLE engine and trans computer(s); you might as well just grab the whole freakin' harness.

 

[RaymondNoodle]

First Guess: It'll be easier to transfer the entire engine-transmission-computer and wire harness from the donor vehicle than to "fix" the existing harness. You're gonna need the original engine and trans computer(s); you might as well just grab the whole freakin' harness.

We have the entire engine/trans harness out off the 2017. I’m talking about the 97

 

[Schurkey]

We have the entire engine/trans harness out off the 2017. I’m talking about the 97

Why keep the '97 engine-trans harness if you have the Donor-Vehicle engine-trans harness? If you've got the 2017 alternator and A/C compressor, you'd want 2017 wires to go with them.

Whatever is NOT being transferred over from the donor might still need the original wiring. Headlights, ABS, turn signals, blower fan, etc.

 

[RaymondNoodle]

I’m wanting to retain
Oil pressure, water temp, rpm
Check engine light if possible,

I assume it would be easier to splice into the 97 harness That’s already in the engine bay to make the gauges work

 

[Jglew82]

Texas Speed did pretty much this exact swap (except theirs was a 6l80). Go check out their youtube channel and look at their "shop truck" videos.

 

[Schurkey]

I’m wanting to retain
Oil pressure, water temp, rpm

I assume it would be easier to splice into the 97 harness That’s already in the engine bay to make the gauges work

Maybe the donor harness has the proper wires and electrical connections for those items. Maybe the dash/gauges system in the donor truck is incompatible with the dash/gauges system in the truck you're modifying. I'm kinda guessing the new truck's gauges are driven directly by the computer through stepper motors. The old gauges are maybe not stepper-motor type. You may find that the sensors for temp and oil pressure are not compatible with the gauges you have.

Check engine light if possible

ABSOLUTELY ESSENTIAL. So far as I know, the Check Engine light isn't driven by any under-hood wiring. Comes from computer across the dash to the light bulb; and is probably in the same harness as the data link.

Beyond that, someone else is going to have to advise you. You're way beyond what I've attempted.

 

[RaymondNoodle]

Texas Speed did pretty much this exact swap (except theirs was a 6l80). Go check out their youtube channel and look at their "shop truck" videos.

I’ve seen it They don’t really go in depth on the wiring