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To introduce myself, I have had several Novas and Chevy 64-66 pickups, and several 240SXs. I have done several motor swaps across all of these vehicles. I have really wanted to another 68-72 Nova, but I wanted the experience of an LS swap in something else to learn what I didn't know. I have always wanted a car from my birth year. When I found a 1980 Corvette L82 NOM that had good paint and many replaced parts including a new SBC I could sell I thought this a great starting point. So starts the education.
I have embarrassed to admit how much time I have read over LS into C3 threads. At some point I believe you just have to buy an engine and start. Have some questions that either were not 100% clear to me or just looking for more info.
1. I am using a 04 GTO LS1 and 4L60. Best crossmember? Should I just weld up the orig and modify it?
2. Does anyone know any shorty headers that I should stay away from? Generally these are all thought to fit?
3. Recommended wiring and ecu service? Who has a reco from a good experience? If I bought HP Tuners could I do what they are doing myself for the tune portion?
4. Is there any connection to body harness from ls harness besides gauges and powering the ls harness?
5. Do I need a kit for the shifter? Is it just to show D,3,2,1? In other words will the stock shifter technically work just fine with no changes?
6. I've heard folks say you should change the cam while its out. Would anyone recommend changing cam if I am leaving the heads stock? This is a just a street car.
7. My engine is DBC. Does the cruise work off of the same one?
8. Is it easier to use my stock AC compressor or the LS one with a aftermarket bracket?
9. Will my harness have wiring in it for the stock GTO fans? If I bought those would those be easier to add in in than aftermarket?
10. Does anyone know of a radiator that has trans cooler built in that is for LS swap to C3 (inlet and outlet are on the correct side)?
11. Is it worth it to buy Tanks tank over stock if I am planning on using Corvette regulator and intank walbro?
I can help on a few questions. I did a 71 C3 LS1/4l60E swap a few years ago.
1. I reused the stock trans cross member. It was kind of a pain routing the exhaust thru the openings in the cross member. I would either fab a new one or go aftermarket that run the exhaust under the cross member.
2. Headers. I used Patriot's for 55-57 chevy mid length. Drivers side fit perfect. The passenger side first tube I modded slightly to clear the engine cross member.
3. I used Howell Fuel Injection on a number of swaps for DBC. Speartech for DBW. Both have worked well. I buy the ECM and the harness together.
4. No other connections. I'm not familiar with the 1980 Speedo, tach or gauges. There maybe some conversion kits out there. I used all Auto Meter replacing my stock gauges.
5. I used a Shift Works conversion for the shifter. Worked well.
6. I didn't put a cam in my LS1. It was a brand new crate and at 350 plus hp the car wasn't slow. But your 04 LS is 14 years old. I'd pull the timing cover and oil pan, put in a new oil pump and timing chain. You will need a new oil pan any ways the GTO pan won't fit. Most use FBody pans and front accessories. If you do a Borgesen steering box conversion I believe you could use a batwing pan off of a C5 Corvette. The Fbody pan did hang down below the crossmember. If you do decide on a bigger cam you will need better springs and push rods.
7. Don't know about this. Most on LS Swaps use aftermarket.
8. I think most end up mounting the AC compressor up high on the passenger side head. I didn't have AC.
9.The wiring harness should have relays for one or two fans depending what on what you want.
10. Don't know about the trans cooler in the radiator. I ran a aftermarket big stacked plate trans cooler right in front of the radiator. Aftermarket radiator. Cross flow type so the inlet and outlet are on the passenger side. Makes for cleaner radiator hose routing.
11. Don't know about this. Guys on LS1 Tech might have some insight on this.
Good luck with the swap.
I can help on a few questions. I did a 71 C3 LS1/4l60E swap a few years ago.
1. I reused the stock trans cross member. It was kind of a pain routing the exhaust thru the openings in the cross member. I would either fab a new one or go aftermarket that run the exhaust under the cross member.
2. Headers. I used Patriot's for 55-57 chevy mid length. Drivers side fit perfect. The passenger side first tube I modded slightly to clear the engine cross member.
3. I used Howell Fuel Injection on a number of swaps for DBC. Speartech for DBW. Both have worked well. I buy the ECM and the harness together.
4. No other connections. I'm not familiar with the 1980 Speedo, tach or gauges. There maybe some conversion kits out there. I used all Auto Meter replacing my stock gauges.
5. I used a Shift Works conversion for the shifter. Worked well.
6. I didn't put a cam in my LS1. It was a brand new crate and at 350 plus hp the car wasn't slow. But your 04 LS is 14 years old. I'd pull the timing cover and oil pan, put in a new oil pump and timing chain. You will need a new oil pan any ways the GTO pan won't fit. Most use FBody pans and front accessories. If you do a Borgesen steering box conversion I believe you could use a batwing pan off of a C5 Corvette. The Fbody pan did hang down below the crossmember. If you do decide on a bigger cam you will need better springs and push rods.
7. Don't know about this. Most on LS Swaps use aftermarket.
8. I think most end up mounting the AC compressor up high on the passenger side head. I didn't have AC.
9.The wiring harness should have relays for one or two fans depending what on what you want.
10. Don't know about the trans cooler in the radiator. I ran a aftermarket big stacked plate trans cooler right in front of the radiator. Aftermarket radiator. Cross flow type so the inlet and outlet are on the passenger side. Makes for cleaner radiator hose routing.
11. Don't know about this. Guys on LS1 Tech might have some insight on this.
Good luck with the swap.
Thanks for the reply. In 80, the exhaust goes under the crossmember already so maybe I will look to modify it. Excited to get started on this, but I may wait until my lift is installed so I can just lift the body off.
Thanks, I've seen this one and the BeCool one, but unless they include the trans cooler this seems to be pretty expensive. Just found this even though it doesn't include fans. This isn't for C3 but I reached out to them to see if they offer something similar.
" Each package includes an electric fan with the temperature switch mounted in the end tank. We also include a steam line connection, custom billet DeWitts radiator cap, and complete electrical wiring kit."
Comes with fans- for the auto version comes with the trans cooler- PLUS they have a steam port!
Thanks for the reply. In 80, the exhaust goes under the crossmember already so maybe I will look to modify it. Excited to get started on this, but I may wait until my lift is installed so I can just lift the body off.
I ran an 80 crossmember in my 77 swap , had to make the bracket from the crossmember to 4L60 anyway so I welded in a piece of 4 inch pipe for the drivers side exhaust pipe to go underneath
I've used Hptuners on my boat install. I'm still a novice at it, but if you're doing a swap using the stock fuel injection, I don't see how you can get by without it. It's not that hard, just time consuming.
First C3, first LS.
