I am moving into a new house on the second of march, and after that dust settles I am going to be picking up a third gen, and looking for a donor ls1 f-body.

I am planning on stripping the whole third gen down to nothing, painting the under carriage, engine bay, and every other component. I want the car to look brand new and factory-ish when done. I also want to swap as much of the 4th gen over as I can, I plan on doing the dash swap as well as custom 4th gen seats and the whole nine yards.

I have been researching this for months and have gained a ton of knowledge but still have a few questions I was not able to get definitive answers on.

1st, is the donor car method the best? I was hoping to get a nice rear ended 4th gen for under 4 grand. I know you can pull truck motors for a lot less than ls1 cars, and they perform the same, but I was planning on using the 4th gen cars transmission, rear end, interior, wiring harness, pedals, clutch master, all of that. I think getting a donor car, and selling everything I do not use off the car and scrapping the car ( or even swapping the third gen rear ect over and making it a roller to keep around for a drag car project if its not wrecked too bad ) would be the best bet. But I have never done this before so please enlighten me. What other parts would I need to purchase save for motor and tranny mounts if I had both cars at my disposal?

2nd, would it make it harder or easier depending on the third gen cars original options? Would it matter if I picked up a 6cyl auto or should I look for a v8 car with a five speed?

3rd, and final until I actually have the cars in hand, would be a compound wiring question. Now I am very confident in my soldering/heat shrinking/ and wire organizational skills, but I haven't done much automotive wiring. What is keeping me from just using the ls1 cars harness as is? Why do I have to modify it? Is it simply to remove things that the third gen will not have? I am not going for a race car here and want to maintain all that I can for creature comforts, like A/C.

I know the dash swaps are a pain, but it seems that all the pain comes from getting the stock cluster to work. I do not want to use the stock cluster. I remember when I had my trans am I frequented the appearance and detailing section years back and someone was making gauge template that fit in the stock dash and let you mount a few smaller gauges as well as a tach and speedo ( auto-meter or the like ). I want to make that, and that being said won't the dash swap mostly consist of hvac work, mounting the dash, and wiring up the after market gauges per manufactures instructions? Simplifying the whole process?

Lastly what about using the whole 4th gens body harness? The cars are similar enough that running the wires back there wouldn't be an issue, and I'm sure a few connectors are different as far as tail lamp lights ect, but that can all be changed, wouldn't using the 4th gen engine and body harness make the whole swap ( including the stock cluster if one chose ) basically plug and play save for switching a few light bulb sockets and that sort of thing?

 

1. donor car is best route, since you can part out everything you dont need to the 3rd and 4th gen crowd, make back a lot of money and get your hands on a lot of the little things you dont need until you're in the thick of it

2. if you can, avoid a factory carbed car. it requires you redo *every* part of the fuel and electrical system. in factory FI setups, you can reuse some of the stock fuse spots if you're handy. you can also make adapters for the fuel lines and reuse the sending unit in the tank. not a deal breaker by any means, but its nice to have the options if yours are in good shape.

3. read all the swap harness posts by Pocket. it will help clear things up. you'll also have to have the pcm reprogrammed to get rid of 4th gen vats, along with any emissions-related error codes.