LS7 Swap
LS7 Swap Hey fellas,
I'm Rob, currently deployed in Afghanistan, will be back in less than 90 days. I've been saving and saving, so during the next 90 days I'm highly considering an LS7 swap into my 04 CTS-V. I found a slightly used LS7 for sale, and am about to purchase it. However I do have some questions before pulling the trigger and hoping someone here can help me out. The LS7 has the dry sump system, but won't come with a wiring harness, ecu/pcm, or full ls7 clutch assembly. I am by no means a mechanically inclined dude. Would the LS7 bolt right up to my tremec T56 trans? Or would I have to look into getting a new one also? I've read that the reluctor wheel must be changed out, and the crank should be rebalanced.
What other pieces (parts/tuning) of the puzzle am i missing that I would have to figure in? Would getting the pcm/ecu swapped and programmed be a royal PITA? I also currently have some kooks 1 3/4 headers on my LS6. Would I be able to reuse them with the LS7? I know most guys would probably say jump up to the 1 7/8, but unless I have a buyer for my 1 3/4 i wouldn't want to throw an extra 1k out there if I didn't have to.
Hopefully you guys that read this can help me understand what else is needed for this kind of swap so I can make an educated decision on this. I would really like to do it, just want to make sure it stays within reason (price wise). Also, if I do end up swapping it out, i will have a used LS6 for sale
Any advice/ suggestions are greatly appreciated. feel free to PM me also. thanks in advance!
I'm Rob, currently deployed in Afghanistan, will be back in less than 90 days. I've been saving and saving, so during the next 90 days I'm highly considering an LS7 swap into my 04 CTS-V. I found a slightly used LS7 for sale, and am about to purchase it. However I do have some questions before pulling the trigger and hoping someone here can help me out. The LS7 has the dry sump system, but won't come with a wiring harness, ecu/pcm, or full ls7 clutch assembly. I am by no means a mechanically inclined dude. Would the LS7 bolt right up to my tremec T56 trans? Or would I have to look into getting a new one also? I've read that the reluctor wheel must be changed out, and the crank should be rebalanced.
What other pieces (parts/tuning) of the puzzle am i missing that I would have to figure in? Would getting the pcm/ecu swapped and programmed be a royal PITA? I also currently have some kooks 1 3/4 headers on my LS6. Would I be able to reuse them with the LS7? I know most guys would probably say jump up to the 1 7/8, but unless I have a buyer for my 1 3/4 i wouldn't want to throw an extra 1k out there if I didn't have to.
Hopefully you guys that read this can help me understand what else is needed for this kind of swap so I can make an educated decision on this. I would really like to do it, just want to make sure it stays within reason (price wise). Also, if I do end up swapping it out, i will have a used LS6 for sale
Any advice/ suggestions are greatly appreciated. feel free to PM me also. thanks in advance! 
Hey Rob,
First off thanks for your service.
Second this will be a sweet swap.
I had just one thing to throw out there.
I think that if you dont use the dry sump you have to cut an inch off the end of the crank.
Im not sure where i heard that, hope i dont sound like an idiot.
Also with the reluctor wheels, yes, but as far as tuning, you just have to get the LS2(GEN IV) conversion kit.
With the headers... I understand not wanted to buy ANOTHER set of Kooks, lol but im sure it would really help.
Good luck.
First off thanks for your service.
Second this will be a sweet swap.
I had just one thing to throw out there.
I think that if you dont use the dry sump you have to cut an inch off the end of the crank.
Im not sure where i heard that, hope i dont sound like an idiot.
Also with the reluctor wheels, yes, but as far as tuning, you just have to get the LS2(GEN IV) conversion kit.
With the headers... I understand not wanted to buy ANOTHER set of Kooks, lol but im sure it would really help.
Good luck.
I echo the thanks for your service.
Several folks make a kit for the various adapters and extensions: Scoggin Dickey, Katech, Lingenfelter come to mind.
Lingenfelter also makes a 58x to 24x reluctor conversion box so no disassembly of the motor is required to change the reluctor wheel, making life (and tuning) much easier.
There is a wet sump conversion kit, you can find it turn key on ebay, easy search.
If you decide to run dry sump, all you have to do is route the lines (you may or may not be able to make the factory LS7 setup work) and figure out where/how to mount the remote tank.
I would only put 1 7/8 headers on that motor myself, maybe 2" if I were feeling cheeky. Kooks or ARH are the only brands I would put on that car, quality is tops. If you have an issue with Kooks, that should make it easy.
Your headers will work fine, maybe not optimized, but you can sure run 'em and make good power, LG has, if I am not mistaken.
Have fun with this and have some pics taken for us!
Several folks make a kit for the various adapters and extensions: Scoggin Dickey, Katech, Lingenfelter come to mind.
Lingenfelter also makes a 58x to 24x reluctor conversion box so no disassembly of the motor is required to change the reluctor wheel, making life (and tuning) much easier.
There is a wet sump conversion kit, you can find it turn key on ebay, easy search.
If you decide to run dry sump, all you have to do is route the lines (you may or may not be able to make the factory LS7 setup work) and figure out where/how to mount the remote tank.
I would only put 1 7/8 headers on that motor myself, maybe 2" if I were feeling cheeky. Kooks or ARH are the only brands I would put on that car, quality is tops. If you have an issue with Kooks, that should make it easy.
Your headers will work fine, maybe not optimized, but you can sure run 'em and make good power, LG has, if I am not mistaken.Have fun with this and have some pics taken for us!
LS7 / V T56 Compatibility John,
Although the bellhousing will bolt up, he'll need a clutch slave spacer ($) or an LS7 slave ($$$$$$$$) because of the V's T56 unique front spacing (~10mm or so rearward) which also requires the use of a V (or truck) pilot bearing instead of the usual Y or F car pilot.
Also, the bellhousing will have to have the notches for the slave line/bleeder increased in depth by a bit more than the spacer (or LS7 slave) offset.
Although the bellhousing will bolt up, he'll need a clutch slave spacer ($) or an LS7 slave ($$$$$$$$) because of the V's T56 unique front spacing (~10mm or so rearward) which also requires the use of a V (or truck) pilot bearing instead of the usual Y or F car pilot.
Also, the bellhousing will have to have the notches for the slave line/bleeder increased in depth by a bit more than the spacer (or LS7 slave) offset.
Last edited by scatillac; Apr 27, 2009 at 06:26 AM.
