Ls swap questions

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Isaac McCaffrey

Junior Member
Joined
Sep 10, 2020
Posts
11
Reaction score
15
Location
Sioux falls, Sd
First Name
Isaac
Truck Year
1977
Truck Model
k10
Engine Size
305
So I have been wondering about repowering my square and my local wrecking yard has this thing call simple part pricing which basically means that you can get a 350 for the same price as an 5.3 so I'm gonna run with that and do an ls swap but I want as much as I possibly can to be from the junkyard what do i need to do a junkyard ls swap the motor is a 5.3 and the trans is a th350 , here is the donor and what can i use off of it for my truck?
You must be registered for see images attach
 

80BrownK10

Full Access Member
Joined
Oct 22, 2019
Posts
1,878
Reaction score
1,240
Location
Greenwood, SC
First Name
Nate
Truck Year
1980
Truck Model
K10
Engine Size
350
Get the wiring harness, the computer and you may as well get the transmission or a modern transmission to get the full benefit from the swap. Make sure you get all the brackets and grab the accessories needed as I don't believe they swap over.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,232
Reaction score
5,167
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
If its a 4x4, you probably don't want to go through the hassle of swapping the trans to a 4l60e. The cheapest swap is to just drop in the 5.3 with the stock computer and harness. You can rework the harness and cut out all the non-necessary stuff and then you will only have something like 4 wires to hook into the truck. You can do your own ECU tuning for about $60 by buying an OBDxPro VT tool and opensource software. You'll need to get swap motor mounts and also convert your fuel system to EFI by either swapping in an 87 TBI fuel tank and sending unit with an EP381 pump or running an external electric pump in-line with the stock fuel system.

You'll also need LS swap headers. There are also some differences between different LS motors. ICT billet has some pretty comprehensive info on the differences.
https://www.ictbillet.com/swap-guide/ls-swap-guide.html
 

Scott91370

Full Access Member
Joined
Apr 2, 2018
Posts
938
Reaction score
910
Location
Burleson, Tx
First Name
Scott
Truck Year
1985
Truck Model
Sierra1500
Engine Size
350
Accelerator pedal? Guess that depends on the engine (I didn't look at the attachment).
 

RoryH19

Full Access Member
Joined
Aug 21, 2015
Posts
1,668
Reaction score
1,082
Location
Texas
First Name
Rory
Truck Year
1987
Truck Model
R10 Silverado SWB
Engine Size
350 TBI
Look at my k5 swap in my signature for some pointers.
 

Camar068

Supporting Member
Supporting Member
Joined
Feb 5, 2014
Posts
4,186
Reaction score
3,068
Location
Kentucky
First Name
David
Truck Year
1986
Truck Model
K10/LM7 5.3/4L60e/np208/3.73/32"
Engine Size
10 yrs Air Force
if it's 4x4 just tap the 4l60e trans adapter for a camaro VSS sensor. Then get a clamp on reluctor wheel for around $100.
 

JBswth

Full Access Member
Joined
Jan 24, 2022
Posts
151
Reaction score
119
Location
Vallejo, California
First Name
James
Truck Year
1973
Truck Model
C25
Engine Size
292 cubic inches
So I have been wondering about repowering my square and my local wrecking yard has this thing call simple part pricing which basically means that you can get a 350 for the same price as an 5.3 so I'm gonna run with that and do an ls swap but I want as much as I possibly can to be from the junkyard what do i need to do a junkyard ls swap the motor is a 5.3 and the trans is a th350 , here is the donor and what can i use off of it for my truck?
You must be registered for see images attach
A 5.3 is smaller than your 350, so it won't have the low-RPM torque as a 350. You might have to gear down, or else it might feel boggy off the line.
 

Latest posts

Forum statistics

Threads
42,332
Posts
913,847
Members
33,832
Latest member
Kipps5000
Top