A few LS1 swap questions
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
A few LS1 swap questions
Hey guys, I'm planning on a LS1 swap soon. 
I have a few questions, as it seems to be a lot of work and I want to get everything correct. Keep in mind I am going from a 2.8 V6 A4.
#1. If I purchase a donor car, other than notching the K member, and cutting for the T-56 to fit, can I swap in the LS1 computer, wiring harness, motor and tranny and rear end? Or is there more I need to do? I've read the FAQs here a few times and I can't seem to find a concrete answer for that question.
#2. At Hawk's site they have a list of connectors and such here. Will I need any of those? And if so which ones?
#3. My current radiator has a crack in it. (LOL) I was planning on using the LS1 rad, I assume it will fit, anything else I will need to know?
#4. I plan on dropping the motor in from the top as I do not have the ability to put the car over it with the K-member. Any hazards and such I need to know?
#5. I plan on using the rear end from the donor car, due to it having disc brakes and posi (IIRC). I assume I will need new brake lines, or can I use what I have?
#6. I know I will need a new fuel pump, which one would be the best choice? Or should I just use the tank from the donor car?
#7. Gauges, I was planning one putting in some white face autometer ones in, will they work correctly with the swap? Or will I need a converter or something for them?
#8. The Y-pipe, could I cut the stock one from the donor car and weld it to fit my car? Or will I need to have one made?
That's what I can remember, if I have more questions I'll post them up. Thanks guys!
I have a few questions, as it seems to be a lot of work and I want to get everything correct. Keep in mind I am going from a 2.8 V6 A4.
#1. If I purchase a donor car, other than notching the K member, and cutting for the T-56 to fit, can I swap in the LS1 computer, wiring harness, motor and tranny and rear end? Or is there more I need to do? I've read the FAQs here a few times and I can't seem to find a concrete answer for that question.
#2. At Hawk's site they have a list of connectors and such here. Will I need any of those? And if so which ones?
#3. My current radiator has a crack in it. (LOL) I was planning on using the LS1 rad, I assume it will fit, anything else I will need to know?
#4. I plan on dropping the motor in from the top as I do not have the ability to put the car over it with the K-member. Any hazards and such I need to know?
#5. I plan on using the rear end from the donor car, due to it having disc brakes and posi (IIRC). I assume I will need new brake lines, or can I use what I have?
#6. I know I will need a new fuel pump, which one would be the best choice? Or should I just use the tank from the donor car?
#7. Gauges, I was planning one putting in some white face autometer ones in, will they work correctly with the swap? Or will I need a converter or something for them?
#8. The Y-pipe, could I cut the stock one from the donor car and weld it to fit my car? Or will I need to have one made?
That's what I can remember, if I have more questions I'll post them up. Thanks guys!
Joined: Apr 2002
Posts: 2,029
Likes: 2
From: Ohio
Car: 88' Iroc-Z
Engine: LQ9
Transmission: T-56
Axle/Gears: 3.42
Re: A few LS1 swap questions
Hey guys, I'm planning on a LS1 swap soon.
I have a few questions, as it seems to be a lot of work and I want to get everything correct. Keep in mind I am going from a 2.8 V6 A4.
#1. If I purchase a donor car, other than notching the K member, and cutting for the T-56 to fit, can I swap in the LS1 computer, wiring harness, motor and tranny and rear end? Or is there more I need to do? I've read the FAQs here a few times and I can't seem to find a concrete answer for that question.
You'll need a t-56 tranny crossmember and have the harness modified to connect to the 3rd gen wiring
#2. At Hawk's site they have a list of connectors and such here. Will I need any of those? And if so which ones?
I'm not sure on those, i havent heard of many using them.
#3. My current radiator has a crack in it. (LOL) I was planning on using the LS1 rad, I assume it will fit, anything else I will need to know?
4th gen will work you'll have to drill a hole in the lower radiator support for it to sit flat
#4. I plan on dropping the motor in from the top as I do not have the ability to put the car over it with the K-member. Any hazards and such I need to know?
It can be done, but most say they have a really hard time getting the oil pan to clear the notch in the kmember because of the angle.
#5. I plan on using the rear end from the donor car, due to it having disc brakes and posi (IIRC). I assume I will need new brake lines, or can I use what I have?
It's been a while since ive done it but i think i used the 4th gen axle lines and the third gen T on the axle
#6. I know I will need a new fuel pump, which one would be the best choice? Or should I just use the tank from the donor car?
You can use the tank from the ls1 car or, a lot of people use the walbro 255lph pump.
#7. Gauges, I was planning one putting in some white face autometer ones in, will they work correctly with the swap? Or will I need a converter or something for them?
I cant answer i am doing a 4th gen dash swap and using the 4th gen gauges.
#8. The Y-pipe, could I cut the stock one from the donor car and weld it to fit my car? Or will I need to have one made?
you'll have to have a custom one made
That's what I can remember, if I have more questions I'll post them up. Thanks guys!
I have a few questions, as it seems to be a lot of work and I want to get everything correct. Keep in mind I am going from a 2.8 V6 A4.
#1. If I purchase a donor car, other than notching the K member, and cutting for the T-56 to fit, can I swap in the LS1 computer, wiring harness, motor and tranny and rear end? Or is there more I need to do? I've read the FAQs here a few times and I can't seem to find a concrete answer for that question.
You'll need a t-56 tranny crossmember and have the harness modified to connect to the 3rd gen wiring
#2. At Hawk's site they have a list of connectors and such here. Will I need any of those? And if so which ones?
I'm not sure on those, i havent heard of many using them.
#3. My current radiator has a crack in it. (LOL) I was planning on using the LS1 rad, I assume it will fit, anything else I will need to know?
4th gen will work you'll have to drill a hole in the lower radiator support for it to sit flat
#4. I plan on dropping the motor in from the top as I do not have the ability to put the car over it with the K-member. Any hazards and such I need to know?
It can be done, but most say they have a really hard time getting the oil pan to clear the notch in the kmember because of the angle.
#5. I plan on using the rear end from the donor car, due to it having disc brakes and posi (IIRC). I assume I will need new brake lines, or can I use what I have?
It's been a while since ive done it but i think i used the 4th gen axle lines and the third gen T on the axle
#6. I know I will need a new fuel pump, which one would be the best choice? Or should I just use the tank from the donor car?
You can use the tank from the ls1 car or, a lot of people use the walbro 255lph pump.
#7. Gauges, I was planning one putting in some white face autometer ones in, will they work correctly with the swap? Or will I need a converter or something for them?
I cant answer i am doing a 4th gen dash swap and using the 4th gen gauges.
#8. The Y-pipe, could I cut the stock one from the donor car and weld it to fit my car? Or will I need to have one made?
you'll have to have a custom one made
That's what I can remember, if I have more questions I'll post them up. Thanks guys!
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
1) Direct quote from the sticky
2) No, you will have enough connectors from the LSx harness. Any others will be needed on a repair basis. Search a JY for any common 90's GM car for the connectors at a fraction of Hawks markup
3) Mounts and hose locations are different, core is thinner than your V6 rad, but it will work. You will use the 4th gen radiator hoses with this rad
4) Need the K-member notch, remove the wiper motor or bust it
5) It'd be a good idea to update the 1989 brake lines dont you think? Dont forget to swap to a disk prop valve and keep in mind the axle length differences
6) Walbro 255. Using the 4th gen tank brings in quite a few extra problems
7) They'll work fine assuming you wire them in correctly
8) Y-pipe must be custom fabbed, no getting around that. Only useful part is the manifold to Y-pipe flanges
Wiring is covered in great detail in the sticky
Nearly all vacuum lines are removed. Large 1/2" port feeds the booster, be sure to swap out the booster check valve from 3/8" to 1/2" like the LS1. Last port in the rear feeds the HVAC system. 3rd gen will have two coming out of the firewall. One fed the bypass valve (removed), other HVAC stuff. Cap the long bypass tube and connect the HVAC line to the intake
Engine mounts can again be purchased or made. The most popular and easiest way to bolt in your new LS1 is by using the fourth gen engine side of the mount and buying the horseshoe adaptor mounts from Hawks or Spohn.
3) Mounts and hose locations are different, core is thinner than your V6 rad, but it will work. You will use the 4th gen radiator hoses with this rad
4) Need the K-member notch, remove the wiper motor or bust it
5) It'd be a good idea to update the 1989 brake lines dont you think? Dont forget to swap to a disk prop valve and keep in mind the axle length differences
6) Walbro 255. Using the 4th gen tank brings in quite a few extra problems
7) They'll work fine assuming you wire them in correctly
8) Y-pipe must be custom fabbed, no getting around that. Only useful part is the manifold to Y-pipe flanges
Wiring is covered in great detail in the sticky
Nearly all vacuum lines are removed. Large 1/2" port feeds the booster, be sure to swap out the booster check valve from 3/8" to 1/2" like the LS1. Last port in the rear feeds the HVAC system. 3rd gen will have two coming out of the firewall. One fed the bypass valve (removed), other HVAC stuff. Cap the long bypass tube and connect the HVAC line to the intake
Joined: Apr 2002
Posts: 2,029
Likes: 2
From: Ohio
Car: 88' Iroc-Z
Engine: LQ9
Transmission: T-56
Axle/Gears: 3.42
Re: A few LS1 swap questions
here is a link. https://www.thirdgen.org/forums/ltx-...p-3rd-gen.html
check out the guide here https://www.thirdgen.org/forums/ltx-...third-gen.html there is a wealth of information and you probably wont have any problems someone hasnt already had.
Last edited by 87CIZ; Sep 4, 2010 at 08:17 AM.
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
Thanks a lot guys. 
I had another question but I can't remember it. 
I had another question but I can't remember it. 
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: A few LS1 swap questions
'91 and '92 cars had rear disc proportioning valves no matter if they had rear drums or not. At least the V8 cars did. I parted out a '91 RS and I think I still have the proportioning valve here if you want to buy it.
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Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
I would, but my LS1 build is a few months in the future. I'm getting my concerns out of the way first.
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
I've come up with another question, what about the LS1 fuses? Anything I should know about those?
Re: A few LS1 swap questions
A fully integrated harness will reuse the stock 3rd gen fuseblock under the dash. It's plenty large enough and has ample wiring in place
Using the 4th gen harness mostly intact requires the 4th gen fuseblock and a few crossover wires making things messy. Both options work great, just how much time are you willing to put into the harness
Using the 4th gen harness mostly intact requires the 4th gen fuseblock and a few crossover wires making things messy. Both options work great, just how much time are you willing to put into the harness
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
A fully integrated harness will reuse the stock 3rd gen fuseblock under the dash. It's plenty large enough and has ample wiring in place
Using the 4th gen harness mostly intact requires the 4th gen fuseblock and a few crossover wires making things messy. Both options work great, just how much time are you willing to put into the harness
Using the 4th gen harness mostly intact requires the 4th gen fuseblock and a few crossover wires making things messy. Both options work great, just how much time are you willing to put into the harness
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
I have another question, how would all my previous questions apply to a LT1 swap? Also, what will be needed to keep my wipers working?
Thread Starter
Joined: Mar 2009
Posts: 2,036
Likes: 28
From: Florida
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: A few LS1 swap questions
PS. Pocket you are amazing, you've got all my questions covered.
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