Ls3 in 2003 chevy silverado
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Teching In
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Ls3 in 2003 chevy silverado I have a 5.3L 2003 chevy silverado with 250,000 miles on it. I am looking a swapping it for a 2009 ls3 from a covette but i have a few questions
1. Will the engine even fit?
2. What wiring harness do i use?
3. Will a custom exhaust have to be made?
4. What transmission should i use?
5. Any other problems i may encounter?
Answers would be greatly appreciated as I don't really know alot about swapping engines. Thank you.
1. Will the engine even fit?
2. What wiring harness do i use?
3. Will a custom exhaust have to be made?
4. What transmission should i use?
5. Any other problems i may encounter?
Answers would be greatly appreciated as I don't really know alot about swapping engines. Thank you.
Physically it is the same engine. No problems installing and bolting to the transmission. Although I would highly recommend a 4L80E if you plan to make good power and hook it to the street.
The exhaust manifolds will bolt right to the LS3, but you really should put in long tube headers since you will be there already, and the LS3 will really want them.
You will need to have the pcm tuned (I think the 5.3 you have is 24 tooth reluctor wheel on the crank and I KNOW the LS3 is a 58 tooth wheel), and you will need to swap a few wiring harness connectors for the different knock sensors and crank sensor.
That is all I know for sure.
The exhaust manifolds will bolt right to the LS3, but you really should put in long tube headers since you will be there already, and the LS3 will really want them.
You will need to have the pcm tuned (I think the 5.3 you have is 24 tooth reluctor wheel on the crank and I KNOW the LS3 is a 58 tooth wheel), and you will need to swap a few wiring harness connectors for the different knock sensors and crank sensor.
That is all I know for sure.
you cant tune from 24 to 58. you need a converter box, or pull the crank and change the wheel.
the knock sensors on the 5.3 are in the valley, on the ls3 they are on the sides. you will need to tap the block and put the 5.3 sensors on the sides, or just turn them off in the tune.
the cam sensor on the 5.3 is in the top rear of the valley, in the ls3 its in the front timing cover. you will need to extend the wire from front to rear.
its a pretty straight forward swap. youre gonna have to figure something out for the throttle body too. there is a converter for that also, but i always see people having problems with them.
the knock sensors on the 5.3 are in the valley, on the ls3 they are on the sides. you will need to tap the block and put the 5.3 sensors on the sides, or just turn them off in the tune.
the cam sensor on the 5.3 is in the top rear of the valley, in the ls3 its in the front timing cover. you will need to extend the wire from front to rear.
its a pretty straight forward swap. youre gonna have to figure something out for the throttle body too. there is a converter for that also, but i always see people having problems with them.
