Author Topic: Ls swap questions  (Read 9875 times)

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Ls swap questions
« on: July 25, 2016, 09:56:01 AM »
Hi

I just had a few questions about doing an ls swap. I was gonna just use a tbi for my 87 k10 but the more ive been looking seems like the ls is the way to go. Ive been looking allover on Craigslist trying to find a whole truck to buy to pull the motor out of but they alll have so many miles. I was talking to a guy who has a 5.3 all torn down and machine shop is checking out the block polishing the crank and he said he has everything else all cleaned and ready to be put back together he wanted 750 with the harrness and cpu. Not sure of thats a good deal or not? How much more would i have in bearings and seals oil pump ect....thought if i was gonna build it i would put 4.8 flat top pistons and was told a ls6 cam would be another thing that would be good to do. Im gonna rebuilt a 700r4 and i have 208 i also will be using...thoughts?

Also as far as the rest of the parts needed to complete the bulid i know i need the plates for the motor mounts around 100 bucks think im might try to make some at work though. The guy i talked to said he would do the harrness and reprogram computer for 450 total. Then i need fuel lines not sure what i need there or what pump id need. And then manifolds looks like 2010 Camaro will work from what i read? And drive shafts can i put the motor 1inch back and not move the trans?

I sure would appreciate any input of thoughts you guy have to offer about this.


Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Re: Ls swap questions
« Reply #1 on: July 25, 2016, 10:43:19 AM »
THats way too much for a junk engine
It's scrap metal   Worth abou 67 cents a pound

Keep looking for a complete donor car

The only reason to not get a complete donor car is if you don't have the room to park it

Learn from my mistakes
We bought a take out engine from a salvage yard
They damaged a lot of items that we had to have
They cracked the oil pan and valve covers
They cracked the starter

  They cut the air intake hose
They cut some of the wiring harness
They cut the throttle cable
 They lied about how many miles were on it , and not Ina small way
They said 160K
When we sent the computer off to get it tuned the VIN in stores in he computer we ran a car fax and the vehicle had 270K on it when it was wrecked

But it does run fine    So don't let the miles scare you
With a complete donor vehicle you should be able to at least hear it run
If it cranks and runs good with no smoke then it should be fine


We used Camaro manifolds and down pipes
We just knocked the innerds out of the cats

We actually had to move the LA engine forward about an inch

Not enough to be an issue with the driveshafts




Sent from my iPhone using Tapatalk

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #2 on: July 25, 2016, 01:19:47 PM »
THats way too much for a junk engine
It's scrap metal   Worth abou 67 cents a pound

Keep looking for a complete donor car

The only reason to not get a complete donor car is if you don't have the room to park it

Learn from my mistakes
We bought a take out engine from a salvage yard
They damaged a lot of items that we had to have
They cracked the oil pan and valve covers
They cracked the starter

  They cut the air intake hose
They cut some of the wiring harness
They cut the throttle cable
 They lied about how many miles were on it , and not Ina small way
They said 160K
When we sent the computer off to get it tuned the VIN in stores in he computer we ran a car fax and the vehicle had 270K on it when it was wrecked

But it does run fine    So don't let the miles scare you
With a complete donor vehicle you should be able to at least hear it run
If it cranks and runs good with no smoke then it should be fine


We used Camaro manifolds and down pipes
We just knocked the innerds out of the cats

We actually had to move the LA engine forward about an inch

Not enough to be an issue with the driveshafts




Sent from my iPhone using Tapatalk

I forgot to metion im gonna put a 4ich lift on too still good? How much did the Camaro manifold cost? I thought it seemed like a lot amd better deal if i can find the whole truck atleast ill know all the parts are there. Did your power steering line bolt up too?

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Re: Ls swap questions
« Reply #3 on: July 25, 2016, 10:26:07 PM »
We paid $50 for the manifolds and downpipes with cats

Your stock Ps pump has a fitting on the back where the hose connects
Remove that fitting and the screw it in place of the fitting on the LS pump and your stock hose will work

We used "team 208 motor sports " for the computer

The harness is not hard if you want to just leave all the unused wires in the harness

If you want to cut open the harness and remove all the un used wires it's better to just pay  someone to do it

I've done a couple and it's quick and easy to just abandon the wires you don't need

Although. Having the same guy that tunes the computer to do the harness and they usually add in a fuse box so all you do it hook up two or three wires

You will need in tank pump and a return line

We flipped the fuel rails around on the engine so the fuel lines come off the passenger front of the engine
To do that you have to remove some plastic tabs from the manifold with a dremel

We used the dirty dingo mounts and had to put one inch spacers under the mounts to get the engine to clear the frame

Unless you want to run 36-37" tires you don't need a 4" lift

You can run 33"s with no lift and 35"s with a 2.5 lift

The LS swap is a lot of work and money if your truck runs good
What year is your  truck ?
If it's a 87 it should have TBI already


Sent from my iPhone using Tapatalk

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #4 on: July 27, 2016, 12:23:44 PM »
We paid $50 for the manifolds and downpipes with cats

Your stock Ps pump has a fitting on the back where the hose connects
Remove that fitting and the screw it in place of the fitting on the LS pump and your stock hose will work

We used "team 208 motor sports " for the computer

The harness is not hard if you want to just leave all the unused wires in the harness

If you want to cut open the harness and remove all the un used wires it's better to just pay  someone to do it

I've done a couple and it's quick and easy to just abandon the wires you don't need

Although. Having the same guy that tunes the computer to do the harness and they usually add in a fuse box so all you do it hook up two or three wires

You will need in tank pump and a return line

We flipped the fuel rails around on the engine so the fuel lines come off the passenger front of the engine
To do that you have to remove some plastic tabs from the manifold with a dremel

We used the dirty dingo mounts and had to put one inch spacers under the mounts to get the engine to clear the frame

Unless you want to run 36-37" tires you don't need a 4" lift

You can run 33"s with no lift and 35"s with a 2.5 lift

The LS swap is a lot of work and money if your truck runs good
What year is your  truck ?
If it's a 87 it should have TBI already


Sent from my iPhone using Tapatalk
Thats not bad for the manifolds i thought they would be a lot more!  Glad the PS will be fine. Id rather have all the extra wires gone and just seems easier to just pay someone and know it right and good to go. From what i seen the dingo mounts are they way to go havnt seen a bad post about them yet!  As far as the lift that just what i want to put on it then gonna run 33s or maybe 35s nothing to crazy going to be my daily driver. The truck is in peices right now basically doing a frame up restoration. I bought a couple parts trucks and thought i would use the 87 tbi but im pretty sure im just gonna do the ls now. Lol especially since I just bought a 99 Silverado last night. 4x4. Broke frame and rear end going out. But drove it home 450bucks....bad new though think its the 4.8. Not sure if ill use that motor or just have this truck for a winter beater but either way it was worth what i paid i figure.

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Ls swap questions
« Reply #5 on: July 28, 2016, 07:22:49 AM »
Nice !
I think 99 was a changeover year though

You could have the vortec 350
Post up a picture of the engine


There's not much difference in the 4.8 and 5.3 and no way to tell them apart
Check the VIN and see what it left the factory with

Let me dig around.   I can post some pics of  my truck with different lifts and tire combos



Sent from my iPhone using Tapatalk
« Last Edit: July 28, 2016, 07:37:15 AM by roundhouse »

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Ls swap questions
« Reply #6 on: July 28, 2016, 07:24:20 AM »
4" lift & 35s

35s will fit with no lift if you trim the lower corner of the fender a little

33s will fit fine with no lift at all

Sent from my iPhone using Tapatalk
« Last Edit: July 28, 2016, 07:35:35 AM by roundhouse »

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #7 on: July 28, 2016, 11:29:43 AM »
4" lift & 35s




35s will fit with no lift if you trim the lower corner of the fender a little

33s will fit fine with no lift at all

Sent from my iPhone using Tapatalk

Well the vin and the sticker on the core support say 4.8. He thought it was a 5.3 but that was the first thing i seen when i opened the hood. But the motor came from his dads truck so might get lucky. Barrowing a bore scope today and gonna check the pistons.
I would post pics but on my phone they are to big. Last time i did it i had to drag out my laptop and do it that way it was a pain.

Ya that looks just right with the 4 inch lift what brand lift?

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Re: Ls swap questions
« Reply #8 on: July 28, 2016, 06:51:47 PM »
No idea on the brand.   We pulled it off a parts truck

The 4.8 likes to rev
So it makes good power
Just at a little higher rpm than the 5.3



Sent from my iPhone using Tapatalk

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #9 on: July 30, 2016, 06:02:57 AM »
You think that 4.8 will have the power i want though to spin some decent size tires? If i do put it in mine i wonder if i decided down the road to do a 5.3 if the wiring/computer would be the same? I know they pretty much are the same just diffrent stroke. Heck i might just use that 4l60e too instead of having my 700 rebuilt but then i have to worry about the driveshafts, tcase and the vss but im sure there are opions for the last two...all about how much moeny i want to spend i guess!

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Ls swap questions
« Reply #10 on: July 30, 2016, 09:12:04 AM »
You think that 4.8 will have the power i want though to spin some decent size tires? If i do put it in mine i wonder if i decided down the road to do a 5.3 if the wiring/computer would be the same? I know they pretty much are the same just diffrent stroke. Heck i might just use that 4l60e too instead of having my 700 rebuilt but then i have to worry about the driveshafts, tcase and the vss but im sure there are opions for the last two...all about how much moeny i want to spend i guess!
I dont think you will be able to tell much  difference between the 4.8 and 5.3
The 4.8 loves to rev higher , so makes almost the same HP just at higher revs

The other issue is axle ratio
Running 33s or 35s with a 3.07 axle ratio is going to make it a real slug
  Most 80s trucks had the 3.08 ratio
     3.73 is what we have with 35s and I'd really like to have 4.56

I have 4.11 axles in my bronco with 35s and its ok but 4.56 would be better

The big expense in the LS swap is all the adapters, exhaust, driveshafts, fuel lines and pump , harness and tune , all the nickel and dime stuff etc etc etc

Once you get it swapped in and running driving and want more power or have some issue with the engine, another engine is about $500
The engine itself is only about 1/4 of the cost of the conversion



Regarding posting pictures
I use the Tapatalk app on my smartphone

Take and upload a pic in no time


Does your truck have the in tank fuel pump for TBI ?

Sent from my iPhone using Tapatalk
« Last Edit: July 30, 2016, 09:22:09 AM by roundhouse »

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #11 on: August 01, 2016, 05:25:46 AM »
Well maybe ill just run the 4.8 then and see how it does like you said i can allways swap it out for a 5.3 if i really wanted too. Is the harness and computer the same?

Ive got 3.42s hoping that will hold up good enough might get some kind of lovker for the rear down the road that would be nice.

Yeah those adapters are not cheap at all hoping i dont have to spend 500 for one to put my 208 behind the 4l60e it came from a 700 so im guessing the splines are the same idk about bolting up though.

Yes i have the 87 with the pump in the tank so all i have to do it get a pump puts out more psi right? I seen a post one here about what one to get. Can i buy steel fuel line in bulk and bend it? Or is there a better way to go with that?

Offline ajdmello

  • Newbie
  • Posts: 60
  • Newbie
Re: Ls swap questions
« Reply #12 on: August 04, 2016, 07:25:16 AM »
Well thanks for all the help roundhouse! Sure do appreciate it! Im hoping to have the truck done next summer. Im sure i will have more questions but you definitely got me started off! Thanks again!

Offline hatzie

  • Site Supporters
  • Junior Member
  • ******
  • Posts: 771
Re: Ls swap questions
« Reply #13 on: August 04, 2016, 01:08:14 PM »
You think that 4.8 will have the power i want though to spin some decent size tires? If i do put it in mine i wonder if i decided down the road to do a 5.3 if the wiring/computer would be the same? I know they pretty much are the same just diffrent stroke. Heck i might just use that 4l60e too instead of having my 700 rebuilt but then i have to worry about the driveshafts, tcase and the vss but im sure there are opions for the last two...all about how much moeny i want to spend i guess!
I dont think you will be able to tell much  difference between the 4.8 and 5.3
The 4.8 loves to rev higher , so makes almost the same HP just at higher revs

The other issue is axle ratio
Running 33s or 35s with a 3.07 axle ratio is going to make it a real slug
  Most 80s trucks had the 3.08 ratio
     3.73 is what we have with 35s and I'd really like to have 4.56

I have 4.11 axles in my bronco with 35s and its ok but 4.56 would be better

The big expense in the LS swap is all the adapters, exhaust, driveshafts, fuel lines and pump , harness and tune , all the nickel and dime stuff etc etc etc

Once you get it swapped in and running driving and want more power or have some issue with the engine, another engine is about $500
The engine itself is only about 1/4 of the cost of the conversion



Regarding posting pictures
I use the Tapatalk app on my smartphone

Take and upload a pic in no time


Does your truck have the in tank fuel pump for TBI ?

Sent from my iPhone using Tapatalk

Just looking at the HP numbers is deceiving.  That's why the auto manufacturers marketing teams use HP rather than torque. 
You will notice the torque difference at lower RPMs. For example... my Gen 8 Impalas.
I own a 2009 Impala SS with the FWD LS4 5.3 and a 2012 Impala LTZ with the LFX 3.6. 
The LS4 has 303 HP at 5600 RPM and 323 ft-lb at 4400 RPM. 
The LFX has 300HP at 6000 RPM and 262 ft-lb at 5300 RPM. 
When I hit the gas at 30MPH the LS4 will shove me right back in my seat and the SS rockets to 80MPH and beyond in a couple seconds.  The LFX is still pretty quick but it takes longer to get there.  Noticeably hotter than the older 3.9 & 3.5 but still not a 325 cube V8.
SVC & wiring mans --> Here http://tinyurl.com/7387BRD-SVCMAN or My Bucket @ http://tinyurl.com/SQ-SVCMAN
Parts & Illustr Books -->http://tinyurl.com/SqParts
GMSTG Textbooks-->http://tinyurl.com/STG-TEXTBK
Radio Manuals-->http://tinyurl.com/DELCORADSVC

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Ls swap questions
« Reply #14 on: August 06, 2016, 08:56:22 AM »
Well maybe ill just run the 4.8 then and see how it does like you said i can allways swap it out for a 5.3 if i really wanted too. Is the harness and computer the same?

Ive got 3.42s hoping that will hold up good enough might get some kind of lovker for the rear down the road that would be nice.

Yeah those adapters are not cheap at all hoping i dont have to spend 500 for one to put my 208 behind the 4l60e it came from a 700 so im guessing the splines are the same idk about bolting up though.

Yes i have the 87 with the pump in the tank so all i have to do it get a pump puts out more psi right? I seen a post one here about what one to get. Can i buy steel fuel line in bulk and bend it? Or is there a better way to go with that?
I swapped pumps inside the tank
used rubber line from the tank to a filter and then to the old factory metal line
Then used more rubber up front  from the factory metal line to the fuel rail
(Which we flipped around so the connections were on the passenger front ,
A little trimming on top of the intake manifold with a sawzall and dremel is required to flip the rail )

We used rubber all the way back for the return line

Let me dig around
I think I have an extra pump
And can take some pics to show what filter I used

Does your donor have a return line ?
Some vehicle had a return line and some didn't


I used the radiator hoses from the donor vehicle

Go ahead and replace the water pump while you have the engine out

I'd transplant the 4.8 and after you get it driving with a good tune that eliminates the torque management and emission stuff
If it doesn't have enough power , swapping engines is easy once you've done all the hard work of transplanting in the fuel lines and computer and and and and

All that transplant stuff takes up all the time and money
A running 5.3 without the harness and computer is about $400 where I live

Sent from my iPhone using Tapatalk
« Last Edit: August 06, 2016, 09:01:45 AM by roundhouse »