TBI LS Swap. Please Help
Thread Starter
Registered User
Joined: Mar 2015
Posts: 5
Likes: 0
From: Greenville, SC
TBI LS Swap. Please Help Hi there guys,
First off I have searched this website all I can and can't find what I'm looking for. With that being said, I'm also on my phone so maybe im limited on capabilities? Idk. Anywhooooooo if you know of link just post it and i wont waste anymore time
I'm committing my first TBI homicide and swapping the ol 350 for a 5.3 in my 95 Tahoe.
The plan is to frshen up the 5.3 completley and throw in a Brian Tooley Racing Stage 2 or 3 cam kit in it. Will probably go with the 2 cause it will be a DD and will pull the yard trailer and all that as well so I dont wanna go tooooo agressive.
I got the engine build, thats no problem. But this is still my first technical LS swap all on my own. So when it comes to the "specifics" on this "specific" build I am lost. Ive done research online but its not a thorough as others. I mean is there a kit? are the mounts easy enough to make? Header clearance?
PCM MODS??? I know I'll need a different PCM but there are arguments over whether or not you gotta use both computer or just the one. LS1 Computer or truck computer? I am gonna buy HP Tuners suite and run it on my Surface Pro.
I guess my nitty Gritty Quesion is,
What hardware do i need to do this swap????
First off I have searched this website all I can and can't find what I'm looking for. With that being said, I'm also on my phone so maybe im limited on capabilities? Idk. Anywhooooooo if you know of link just post it and i wont waste anymore time
I'm committing my first TBI homicide and swapping the ol 350 for a 5.3 in my 95 Tahoe.
The plan is to frshen up the 5.3 completley and throw in a Brian Tooley Racing Stage 2 or 3 cam kit in it. Will probably go with the 2 cause it will be a DD and will pull the yard trailer and all that as well so I dont wanna go tooooo agressive.
I got the engine build, thats no problem. But this is still my first technical LS swap all on my own. So when it comes to the "specifics" on this "specific" build I am lost. Ive done research online but its not a thorough as others. I mean is there a kit? are the mounts easy enough to make? Header clearance?
PCM MODS??? I know I'll need a different PCM but there are arguments over whether or not you gotta use both computer or just the one. LS1 Computer or truck computer? I am gonna buy HP Tuners suite and run it on my Surface Pro.
I guess my nitty Gritty Quesion is,
What hardware do i need to do this swap????
Staging Lane
Joined: Dec 2006
Posts: 70
Likes: 1
From: Minneapolis
Here's a link.
This swap has been done a million times, the info is out there. The link above has tons of links attached, and the first one has a list of basic parts in the 1st post. Try searching gmt 400 ls swap, OBS ls swap, suburban/tahoe ls swap, etc.
Fuel - Since you have a 95', you will have to upgrade your fuel to get the required pressure to run the LS. 99'-04' have hi psi pump, and have a separate regulator inline to the fuel rail, 05'+ have the pump and regulator as an assembly, in the tank.
Trans - It's possible your trans will work, but being that it's an early 4L60e, I'd recommend going to a LS 4L60e, it should have the updated converter and should be plug and play. You didn't say if it were 4wd, manual shift or e-shift, might be better off getting an entire pullout to make it easier. If you keep your 60e, you'll need to extend the flywheel out in order to compensate for the difference from SBC to LS, 2 ways to do it. Curved flywheel and a crank support snout or a flat flywheel and an 4L80e crank spacer and longer bolts.
Mounts - In order to keep the drive train in the same spot, dirty dingo has adjustable engine mounts that allow you to keep the existing crossmember, mounts, driveshafts, etc. If you want AC, you will need to notch the frame for the factory low mount AC compressor, or you can buy an AC relocation bracket.
Electrical - The last thing would be wiring, very little of your existing wiring will stay, you're better off either having one built, or take a factory harness and rework it for your setup, and build a standalone. You don't need any special programing for your setup, I don't see why you couldn't run the truck PCM and tune, the MAF can compensate for cam/head differences. The LS1 computer wouldn't be any benefit to you, your not running a 5.7. At a bare minimum, you'll need the anti-theft removed to at least start it. Lt1swap.com is a great website to gather all that information, and he can also setup almost any PCM with a canned tune for your setup provided he has the specs. There's really 2 ways to run the PCMs, you can run the TBI side by side with the LS, it'll mostly be in charge of running the dash, speedo, etc. Or you would remove the TBI PCM, and solely run the LS PCM. You can either remove the pins from the TBI PCM for the Vehicle Speed Sensors, 4L60e, MIL/CEL, fuel pump relay, etc., these you will be re-pin into the LS PCM. Or you would run a completely new harness and just tie into the left over wiring from the TBI. The LS PCM can do almost anything the TBI can do, so all the TBI stuff can be powered by the LS without issue, plus you can remove the mechanical fan and run eFans, but you'll need to turn the eFan on the PCM, trucks usually don't have eFans, so they don't usually have it turned on.
Why try to flex a 5.3 when you could get a 6.0, especially when you're pulling a trailer regularly? Hope that helps, good luck.
This swap has been done a million times, the info is out there. The link above has tons of links attached, and the first one has a list of basic parts in the 1st post. Try searching gmt 400 ls swap, OBS ls swap, suburban/tahoe ls swap, etc.
Fuel - Since you have a 95', you will have to upgrade your fuel to get the required pressure to run the LS. 99'-04' have hi psi pump, and have a separate regulator inline to the fuel rail, 05'+ have the pump and regulator as an assembly, in the tank.
Trans - It's possible your trans will work, but being that it's an early 4L60e, I'd recommend going to a LS 4L60e, it should have the updated converter and should be plug and play. You didn't say if it were 4wd, manual shift or e-shift, might be better off getting an entire pullout to make it easier. If you keep your 60e, you'll need to extend the flywheel out in order to compensate for the difference from SBC to LS, 2 ways to do it. Curved flywheel and a crank support snout or a flat flywheel and an 4L80e crank spacer and longer bolts.
Mounts - In order to keep the drive train in the same spot, dirty dingo has adjustable engine mounts that allow you to keep the existing crossmember, mounts, driveshafts, etc. If you want AC, you will need to notch the frame for the factory low mount AC compressor, or you can buy an AC relocation bracket.
Electrical - The last thing would be wiring, very little of your existing wiring will stay, you're better off either having one built, or take a factory harness and rework it for your setup, and build a standalone. You don't need any special programing for your setup, I don't see why you couldn't run the truck PCM and tune, the MAF can compensate for cam/head differences. The LS1 computer wouldn't be any benefit to you, your not running a 5.7. At a bare minimum, you'll need the anti-theft removed to at least start it. Lt1swap.com is a great website to gather all that information, and he can also setup almost any PCM with a canned tune for your setup provided he has the specs. There's really 2 ways to run the PCMs, you can run the TBI side by side with the LS, it'll mostly be in charge of running the dash, speedo, etc. Or you would remove the TBI PCM, and solely run the LS PCM. You can either remove the pins from the TBI PCM for the Vehicle Speed Sensors, 4L60e, MIL/CEL, fuel pump relay, etc., these you will be re-pin into the LS PCM. Or you would run a completely new harness and just tie into the left over wiring from the TBI. The LS PCM can do almost anything the TBI can do, so all the TBI stuff can be powered by the LS without issue, plus you can remove the mechanical fan and run eFans, but you'll need to turn the eFan on the PCM, trucks usually don't have eFans, so they don't usually have it turned on.
Why try to flex a 5.3 when you could get a 6.0, especially when you're pulling a trailer regularly? Hope that helps, good luck.
