LS swap

[RoryH19]

I also went 6.0 LS with 4l65e from an 04 Escalade. Did all of my own work. You can see my thread below.
As mentioned before you will need to find a t-case (np241c) and gauge cluster from a 90-91 Blazer/Sub.
I also use a 90's 6.5ltr gas pedal since I have DBW for the factory look.
Mine is a full restoration, finishing my interior now.

The big question would be, which is easier...

Hands down, pull the old sbc and replacing with another.

 

[Craig Nedrow]

Here is a little more for thought. I have a bunch of motors, sbc, lq4, ls1's. Swapped a BBC 454 into my 73 K20 earlier in the year. I am a farmer and a retired journeyman machinist. After running this around all summer, towing 8000 lbs of hay, horse trailers etc., love the 454. Main thing is it is a easy bolt in, low in cost, gets about the same mileage, and the torque....plus good vacuum. Even though I have the stuff to swap in a LS style, I went with the BBC. 1500. with a rv cam, bearings, rings, heads, tight and good oil pressure. Also you need to use a BBC fuel pump as the sbc arm is shorter. Holly 4160 converted to 4150. Here is the build thread:

https://www.gmsquarebody.com/threads/1973-k20-350-to-454-swap.29840/

 

[SquareRoot]

for me its was easy en not so expensive..yes i do all the swap my self include wiring!

so this my cost:

LQ4 6L 2004 $500 tax in (kenny-U-pull)
4L80E 2006 $198 tax in (Kenny-U-pull)
Tejas Steel work motor mounts $100
Wiring harness and PCM $0 (old scrap '99 GMC lying aroud my brother garage)
few gasket, trans mount, new alternator ect.... +- $500
i can give you a another $500 for part i don't remember
Total: $1698

Re-Sale my old 6.2 diesel and 700R4 trans $1000
and +- $500 of different others part re-sale

so if you do the math in my case it was a good choice to swap a economic and relyable 350hp pure stock no mod anywhere.. and lot of fun to do it all my self (including remove LS trans and engine at the junkyard lolll)

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SWEEETT!!!! LS SWAP! This will really piss @AuroraGirl off.

 

[AuroraGirl]

SWEEETT!!!! LS SWAP! This will really piss @AuroraGirl off.

i dont hate LS so much as I hate how overdone and the idea is just a meme at this point. Ill get excited when i see a 1942 ford sherman tank engine swapped into a square

 

[Daveo91Burb]

You could always consider rebuilding the 350 you have or another cheap core motor. Options are numerous: stroke it to a 383, vortec or aluminum heads, roller cam, etc. If you go with a core, go with a late model TBI or even a Vortec 350 -- they still have the mechanical fuel pump bosses if you want to stay carb.

 

[Green79Scottsdale]

I think the main questions to ask yourself are...

Are you doing the work yourself? If you are, you better get to doing some deep research before jumping in.

What are you intended uses for the truck? Daily driver with lots of miles every year? Or restore and only put on a couple thousand miles a year? Daily with lots of miles... LS. Not to many miles... rebuild the ole SBC.

 

[TPISly-C10]

SWEEETT!!!! LS SWAP! This will really piss @AuroraGirl off.

my goal whas not to piss anybody off! lolll just give the guy an option!

 

[Kelvin]

i dont hate LS so much as I hate how overdone and the idea is just a meme at this point. Ill get excited when i see a 1942 ford sherman tank engine swapped into a square

They are just the modern version of what the sbc 350 has always been. Cheap, plentiful, and an abundance of aftermarket parts and knowledge to go along with it. I never heard anyone call the sbc 350 a meme when guys were stuffing them into Harleys and snow blowers. Back then, if you wanted to stick a V8 in something, you used a chevy 350 because it just made sense. Today an LS just makes sense because there are more of them. As for replacing a 350 with a 5.3, well, it just makes sense. Less weight, more MPG and easier to find.

 

[OEMBent]

A short while back a member here did a nice job of documenting his swap. Lots of great info in this thread: https://www.gmsquarebody.com/threads/5-3-lm7-going-in-my-87.27558/

That was a good thread. Though it may have had the opposite results for me. I have not always been the best fabricator/engineer. I prefer to rebuild what I have. If it was there originally, I can take it apart and put it back together. If I don't find a truck already done in the engine area, it will be getting an old school(original) powertrain! I might switch it from carb to FI though.

 

[AuroraGirl]

They are just the modern version of what the sbc 350 has always been. Cheap, plentiful, and an abundance of aftermarket parts and knowledge to go along with it. I never heard anyone call the sbc 350 a meme when guys were stuffing them into Harleys and snow blowers. Back then, if you wanted to stick a V8 in something, you used a chevy 350 because it just made sense. Today an LS just makes sense because there are more of them. As for replacing a 350 with a 5.3, well, it just makes sense. Less weight, more MPG and easier to find.

I will stick with a sbc because I have a few already no need in another power plant to pay around, I have trans that don’t need adapters for sbc, and even tho you can carb an LS, there is a beauty to the simplicity of sbc and beauty. But I definitely would be using an LS IF I was working with a gmt800 or newer, just because it’s what it already has and it’s easier(made for application).

The only situation I’d consider a LS to square is if I got an 4l80e or a nice manual and it came with an engine with harness etc like, it’s a lot closer to out that in as a unit than trying to then go super custom

but if I just had a trans, I’d adapt to sbc ngl. Then there is big blocks, can’t forget those guys

 

[JoeR Jr]

That was a good thread. Though it may have had the opposite results for me. I have not always been the best fabricator/engineer. I prefer to rebuild what I have. If it was there originally, I can take it apart and put it back together. If I don't find a truck already done in the engine area, it will be getting an old school(original) powertrain! I might switch it from carb to FI though.

I am in the same boat as you. I can't fabricate a thing. I just don't have the imagination for it. Thankfully you can purchase everything you need for this swap. It's a bolt in. I'm not trying to convince you to do it, because there's no wrong choice here. Just don't let the fabrication thing stop you. I've got 27k miles on my swap now, with no regrets.
Joe

 

[OEMBent]

I am in the same boat as you. I can't fabricate a thing. I just don't have the imagination for it. Thankfully you can purchase everything you need for this swap. It's a bolt in. I'm not trying to convince you to do it, because there's no wrong choice here. Just don't let the fabrication thing stop you. I've got 27k miles on my swap now, with no regrets.
Joe

Good to know. I'll probably be less intimidated as I learn more about the LS motors. I just have experience building old school engines.

 

[Bextreme04]

i dont hate LS so much as I hate how overdone and the idea is just a meme at this point. Ill get excited when i see a 1942 ford sherman tank engine swapped into a square

Pfffff... you dont want a 42 Sherman tank engine. You want the modern version of the M60 engine that is still in production for the M88A2 recovery vehicles. It's made by Continental Engines, and is a 1791 cubic inch, air cooled, turbo-supercharged, v-12, diesel. 1,050hp @ 2400RPM and 2500lb-ft of torque @ 1900RPM

The good news is that it's air cooled and doesn't have any kind of electronic controls, so minimal extra stuff needed for a swap... bad news is that it weighs about 5,100lbs and is massive, so you would probably need to mount it in the bed... and try to figure out a transmission option(the transmission that's in the M88 is a 3 speed, tops out at 25mph, weighs a few thousand pounds by itself, and takes about 30 gallons of 30w oil)

 

[Bextreme04]

Good to know. I'll probably be less intimidated as I learn more about the LS motors. I just have experience building old school engines.

They are actually pretty simple. A basic swap will only need to tie 3 or 4 wires into the old truck harness, everything else is self contained and would stay the same on your truck. The easiest way is to get a donor with the entire engine/trans/harness/ECU from a 99-02 truck and swap the whole mess over. Then it just becomes a matter of handling speedometer and fuel delivery in the old truck. I found an entire 91 gauge cluster to use in my truck locally for $60. I'm using a single 31 gallon TBI blazer tank and sending unit and reusing the hard lines and fuel pump from my 97 Suburban donor. Corvette filter/regulator inline for fuel pressure regulation. Then I'm using a Gen VI 454/4L80E also from the 97 Suburban donor and have converted it to LS style coil packs and a 99-2002 LS 0411 ECU. It will be running on a modified LS operating system that I've reworked myself using an OBDX Pro VT tool($60) and free software(PCM Hammer, LS Droid, TunerPro RT).

You can certainly do it much cheaper and easier with just an engine and computer/harness. Keep the stock transmission and source a TBI fuel tank(you need the interior baffle) and the TBI sending unit and EP381 pump. The only other thing you would need is special motor mounts and those are only about $100.

 

[Brett77]

I agree with Benardo the TH400 behind a big block.