HELP LS Swap Wiring / Transmission Control Advice

81camel

Apprentice
May 16, 2023
68
70
18
So I have a lead on a local 4.8 with a 4L80E that I'm considering buying, but I'm trying to decide what I'm all going to need and the order I'm going to do it in.

I'm not too worried about budget overall, but it just can't be all at once. What I mean by that when I do the swap, the "bigger" things I expect I'm going to need to do are.
  • Exhaust
  • Radiator
  • Fuel System
  • Cross Member
  • Wiring/Harness/ECU/Trans Controller
  • Driveshaft
I would like this to not take 3 years to do because of the cost, so I'm thinking that I would swap in the 4L80E in first (and keep my SBC 350 for now), which would take care of the Cross Member and Driveshaft.

The part that has me hung up is the electrical part. My final plan would be to be using the Holley Terminator X for the LS. I know the Terminator X "Max" version can also control the transmission which sounds nice. Or I could do with a separate Trans Controller for lower cost now, and then add on the Terminator X when I add the LS. What I don't know is, can you use the Terminator X Max with just a transmission? Is a dedicated trans controller better than the terminator x max?

The wiring harness is another part that worries me. The wiring in my car current is very modified and old and so I would be wanting to do a new harness. But I'm not sure I want to jump to rewiring the whole car.
Would it be a terrible idea to get a standalone LS wiring harness that is designed for the Terminator and then later on get a new harness for the rest of the car? I'm not necessarily looking for plug and play. Not afraid of modifying wiring, but I would like to be able to do things in stages so that I can replace/swap some parts, drive the car and enjoy it, and then do more later on.

So bottom line I guess the questions I'm looking for advice on are,
  1. Can you use the Terminator X Max with just a transmission?
  2. Is a dedicated trans controller better than the terminator x max?
  3. Would it be a terrible idea to get a standalone LS wiring harness that is designed for the Terminator and then later on get a new harness for the rest of the car?
  4. Is any of my thoughts and plan above seem totally stupid?

Thanks is advance!
 
The whole car doesn't need to be rewired, you just have to figure out what gauges you are using and power/ground whatever you install to run the engine and transmission.

Literally is that simple it's just a matter of what you want to use. I don't know enough about the Termi X to know how good it is running electronic transmissions or how it's programmed.

I use the GM factory wiring and an 0411 PCM because I've been using HP Tuners since 2008, and for what I have built it works perfectly with the Gen III LS stuff.

Build thread of my SS if you want some ideas on parts to use.

 
That is what I was thinking about with the harness part. It looked to me that chassis vs engine can be completely separate apart from a few things. But going down the google rabbithole I started getting worried that I was going to hate myself down the road.
I like the feeling of having things clean and fresh so that was why I was thinking a standalone harness and then modify from there as needed.

is A/C something to really worry about? I dont have working A/C right now but plan to put in a Vintage Air system yet.


You car looks incredible btw!
 
an aftermarket trans controller alone is around
5-700 depending on brand, which is going to be eventually useless with your future setup when you go with the terminator x max for the 4.8
To control both engine and transmission.
The system is made to control the engine first, with transmission control as an add on.

You will be purchasing some parts that aren’t cheap that will only work for the individual setup you have at the time. You may as well just wait and do it all together once, with the correct stall/gearing/standalone/fuel system/exhaust/cooling system since almost nothing transfers over to the new setup as much as you don’t want to do it that way, All or nothing type of deal which will make the whole swap go so much easier in the end anyway instead of all the re-work.
 
Sounds like a lot of unnecessary work and money spent. I'd urge you install the LS/80e combination together.
 
Sounds like a lot of unnecessary work and money spent. I'd urge you install the LS/80e combination together.
haha, yeah... I've been getting convinced by others as well.

Thats likely what is going to happen. But sticking with stock ECU. will consider terminator X in the future when I do a rebuild.
 

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