LS swap help with parts list
- Thread starter NCTTA
- Start date
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Charlie
Mopar by Birth. Chevy by Choice.
- Joined
- Aug 2, 2017
- Posts
- 1,837
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- 910
- Location
- Euless, Texas
- First Name
- Don
- Truck Year
- 1974
- Truck Model
- Cheyenne 10 LWB
- Engine Size
- 350/TH350/AC/4 BBL Quadrajet
rpcraft
Full Access Member
- Joined
- May 31, 2016
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- 1,329
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- 509
- Location
- Texas
- First Name
- Robert
- Truck Year
- 1985
- Truck Model
- Jimmy
- Engine Size
- LS 6.0 364 CID
Just to speed up your info search rather than waiting on feedback here go on facebook and look up the group called LS Swapped Square Body GM Trucks ('73-'86 C/K & '87-'91 R/V). Look in the flies section and read up there and ask questions.
Plan on parsing the info accordingly
If you want to go the EFI route plan on replacing your transmission with a more modern 4l60E. The 700r4 wasn't really too great when it was new and chances of it surviving any length of time behind the LS motor without feedback from the PCM is not too great even if you use the adapter for a drive by cable setup (bowtie overdrives) and it won't work at all with the DBW setup. If you choose to run your LS swap with a carb setup plan on spending about another 600 bucks on the intake, MSD setup and an adapter for your q-jet. After that the 700R4 is just like it was on your truck, you just want to make sure the TV cable is adjusted 100 properly or your trans will get fried (as with any 700R4). If you stick with your 700R4 and go that route you will just really need to get a snout adapter for the Torque converter to fit into the flex plate and then you may need to oblong the mounting holes on your flexplate some (the bolt pattern changes slightly on the Gen 3 flexplates)
You can usually find drop out motors with a trans for between 800 to 1200 bucks, depending on mileage but that should include the harness, the PCM, and the O2 senors. if you are having the motor pulled make sure they include the exhaust past the front o2 bungs. If you are budget minded you can weld the exhaust on your current rig to the old one with a little fixing and you won't really need to change too much there (unless you want to spring for headers and custom exhaust)
There is a source for Motor mounts called Tejas steelworks and they do a good job of sliding the engine forward but it also slides the transmission forward, the crossmember, and then you need a custom driveshaft. Others will claim to leave the trans in place, but the consequence is that you end up having to notch the engine crossmember and the motor is super close to the firewall and can cause issues with the AC condensor box. Also, the stock c10 driveshaft is pretty weak behind the LS so you want to do a beefier driveshaft anyways. You can usually get one out of a modern z71 and have it shortened and that fits the trick. I highly recomend this after seeing a few swaps done with various mounts because the Tejas mounts on a 2wd truck seem to really be the best solution I have seen and the designer offers a lot of support. You can mail order your PCM tune to whomever answers your call for it. Usually you can get a decent tune for around 75 and that removes all the security stuff as well as loads a base tune on the PCM. You can diy your harness by going to lt1swap.com and studying up. I highly recommend this because it helps you learn the trouble shooting. Alternatively I have recently seen some plug and play third gen LS harnesses for a 4l60E swap on ebay and from all accounts they look to be a solid unit for around 400 bucks but that is 400 bucks vs free (not including some fuse and harness tape type stuff)
As far as the radiator goes you can use your stock one and it should work fine. The LS motor has a steam line that needs to be hooked up somewhere but there are adapters that will put it in the hoses...
There's a ton more to know, hopefully you are just doing a 2wd swap. Feel free to PM me and I will help answer other questions you might have but that Facebook site has a ton of useful info (as well as plenty of poeples opinion and useless info, lol). The admins do a pretty good job of policing the **** birds and keeping the mal-contents at bay, but you know how facecreep can be.
Plan on parsing the info accordingly
If you want to go the EFI route plan on replacing your transmission with a more modern 4l60E. The 700r4 wasn't really too great when it was new and chances of it surviving any length of time behind the LS motor without feedback from the PCM is not too great even if you use the adapter for a drive by cable setup (bowtie overdrives) and it won't work at all with the DBW setup. If you choose to run your LS swap with a carb setup plan on spending about another 600 bucks on the intake, MSD setup and an adapter for your q-jet. After that the 700R4 is just like it was on your truck, you just want to make sure the TV cable is adjusted 100 properly or your trans will get fried (as with any 700R4). If you stick with your 700R4 and go that route you will just really need to get a snout adapter for the Torque converter to fit into the flex plate and then you may need to oblong the mounting holes on your flexplate some (the bolt pattern changes slightly on the Gen 3 flexplates)
You can usually find drop out motors with a trans for between 800 to 1200 bucks, depending on mileage but that should include the harness, the PCM, and the O2 senors. if you are having the motor pulled make sure they include the exhaust past the front o2 bungs. If you are budget minded you can weld the exhaust on your current rig to the old one with a little fixing and you won't really need to change too much there (unless you want to spring for headers and custom exhaust)
There is a source for Motor mounts called Tejas steelworks and they do a good job of sliding the engine forward but it also slides the transmission forward, the crossmember, and then you need a custom driveshaft. Others will claim to leave the trans in place, but the consequence is that you end up having to notch the engine crossmember and the motor is super close to the firewall and can cause issues with the AC condensor box. Also, the stock c10 driveshaft is pretty weak behind the LS so you want to do a beefier driveshaft anyways. You can usually get one out of a modern z71 and have it shortened and that fits the trick. I highly recomend this after seeing a few swaps done with various mounts because the Tejas mounts on a 2wd truck seem to really be the best solution I have seen and the designer offers a lot of support. You can mail order your PCM tune to whomever answers your call for it. Usually you can get a decent tune for around 75 and that removes all the security stuff as well as loads a base tune on the PCM. You can diy your harness by going to lt1swap.com and studying up. I highly recommend this because it helps you learn the trouble shooting. Alternatively I have recently seen some plug and play third gen LS harnesses for a 4l60E swap on ebay and from all accounts they look to be a solid unit for around 400 bucks but that is 400 bucks vs free (not including some fuse and harness tape type stuff)
As far as the radiator goes you can use your stock one and it should work fine. The LS motor has a steam line that needs to be hooked up somewhere but there are adapters that will put it in the hoses...
There's a ton more to know, hopefully you are just doing a 2wd swap. Feel free to PM me and I will help answer other questions you might have but that Facebook site has a ton of useful info (as well as plenty of poeples opinion and useless info, lol). The admins do a pretty good job of policing the **** birds and keeping the mal-contents at bay, but you know how facecreep can be.
