5.3 vs 5.7 questions for swap
03-02-2007, 07:52 PM
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5.3 vs 5.7 questions for swap Hey I'm new here and also to the LS1 world so please forgive my newbishness. I've been doing a lot of research into the LS1 240SX swap ever since I first saw that lime green monstrosity on ebay. Fast forward a bit and now they are becoming more and more popular and a lot closer to becoming "bolt on" in a sense.
After much research it seems to me that the cost to power ratio is a lot better with the 5.3 vortec than the 5.7 LS1. Which brings me to my questions.
Will a GTO oil pan bolt up to the 5.3 like it will the LS1? Will LS1 headers bolt onto the 5.3 or are the ports different sizes? I would probably be using the Hinson headers unless I can find someone locally with "mad tyte skillz" that can weld some up for me. I am pretty sure I can use an LS1 flywheel and T56 with no trouble on the 5.3 right? As well as the LS6 (or LS1) intake manifold? I know the engines are pretty similar but I'm not exactly sure whats different. As far as the engine accessories go, will the LS1 accessory brackets bolt onto a 5.3? I really don't know how the accessories are mounted on the 5.3 but I assume they are different due to the different vehicles they come out of. My only other question would be wiring. I read up on a few 5.3 wiring threads last night on here, some of which made it seem real easy. Would an LS1 wiring harness and PCM work with the 5.3 engine? My goal is to do the 5.3 swap and then later down the line swap in the LS1. What are my best options? Thanks.
Mike
After much research it seems to me that the cost to power ratio is a lot better with the 5.3 vortec than the 5.7 LS1. Which brings me to my questions.
Will a GTO oil pan bolt up to the 5.3 like it will the LS1? Will LS1 headers bolt onto the 5.3 or are the ports different sizes? I would probably be using the Hinson headers unless I can find someone locally with "mad tyte skillz" that can weld some up for me. I am pretty sure I can use an LS1 flywheel and T56 with no trouble on the 5.3 right? As well as the LS6 (or LS1) intake manifold? I know the engines are pretty similar but I'm not exactly sure whats different. As far as the engine accessories go, will the LS1 accessory brackets bolt onto a 5.3? I really don't know how the accessories are mounted on the 5.3 but I assume they are different due to the different vehicles they come out of. My only other question would be wiring. I read up on a few 5.3 wiring threads last night on here, some of which made it seem real easy. Would an LS1 wiring harness and PCM work with the 5.3 engine? My goal is to do the 5.3 swap and then later down the line swap in the LS1. What are my best options? Thanks.
Mike
03-02-2007, 10:12 PM
#2
The GTO oil pan will bolt onto the LS1, but you will also need the GTO pickup, windage tray, dipstick and dipstick tube.
LS1 headers will bolt to a 5.3L.
So far everything is the same if you use the 5.3L or 5.7L.
The flywheel for a 5.7L should bolt to the 5.3L
The intake manifold will bolt on, but the injectors from the truck will not fit, neither will the fuel rails.
The accys are completely different between the 5.3L and 5.7L. You can bolt either set of accys to either motor. To change over you will need all the accy brackets and bolts, a f-body waterpump, powersteering pump, alternator, crank pulley/balancer and an A/C compressor and mount if you are going to run it.
You can use a f-body computer and harness to run a 5.3L, but you will have to retune the computer. You will also need truck coil harnesses (they will plug into the f-body engine harness). I think some of the connectors on the sensors may be different so you may need to change some of the sensors, but I`m not positive about that.
The truck motors do offer a lower buy in price, but if you factor in having to find a complete set of f-body accys, a wiring harness and the fact that you would later like to change to a f-body LS1 anyway I think that you would be money and grief ahead by just buying a f-body LS1 motor from the start. You could sell off the truck accys, computer and wiring harness to offset some of the cost, but the truck stuff is not as valuable as the f-body parts.
LS1 headers will bolt to a 5.3L.
So far everything is the same if you use the 5.3L or 5.7L.
The flywheel for a 5.7L should bolt to the 5.3L
The intake manifold will bolt on, but the injectors from the truck will not fit, neither will the fuel rails.
The accys are completely different between the 5.3L and 5.7L. You can bolt either set of accys to either motor. To change over you will need all the accy brackets and bolts, a f-body waterpump, powersteering pump, alternator, crank pulley/balancer and an A/C compressor and mount if you are going to run it.
You can use a f-body computer and harness to run a 5.3L, but you will have to retune the computer. You will also need truck coil harnesses (they will plug into the f-body engine harness). I think some of the connectors on the sensors may be different so you may need to change some of the sensors, but I`m not positive about that.
The truck motors do offer a lower buy in price, but if you factor in having to find a complete set of f-body accys, a wiring harness and the fact that you would later like to change to a f-body LS1 anyway I think that you would be money and grief ahead by just buying a f-body LS1 motor from the start. You could sell off the truck accys, computer and wiring harness to offset some of the cost, but the truck stuff is not as valuable as the f-body parts.
03-02-2007, 10:27 PM
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Thanks for the detailed reply. I see what you mean about the added cost. All the little stuff adds up fast, not to mention its a pain in the butt to source all that stuff seperately. Guess I'll have to think about this one a bit more. The local LKQ here has a 5.3 for 500 bucks. Pretty sure that doesnt include any accessories or PCM or anything though.
03-02-2007, 10:42 PM
#4
No problem, if your swap allows you to use the truck accys and intake the truck motors can be a real bargain. But once you have to start buying parts it can add up real quick. When I did my swap I paid $800 for my motor with the PCM, wiring, and all the accys except the A/C compressor. I thought I had everything with the motor but I was missing the starter bolts......when I went to the dealer to buy them they were $20 for the two bolts (I later found out that dealer was overcharging, and GM list was $6 each not $10, but even at $6 a bolt it can add up pretty quick). I have seen a couple people end up getting away pretty cheap by putting together a motor from parts, but it seems like a lot more of the people that try it end up spending just as much if not more than if they just bought a complete engine with all the wiring, PCM, and accys. It all depends on luck.
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03-09-2007, 12:17 PM
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I am going to run a 5.3... here are some of the things that i have had to do
http://www.cardomain.com/ride/2163805/6
http://www.cardomain.com/ride/2163805/6
07-01-2021, 06:42 PM
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5.3 to a 5.7 pick up gmc Hello i had a question for you guys okay i have a 5.3 i pulled out my sierra and im replacing it with the 5.7 out of my tahoe now i swapped them and the trans fits and its all put together but now its not starting and its blowing all the fuses and the coil is not getting any kind of spark can you help me out. And swapped out trans case from the 5.7 with the 5.3 i have it all put together but im still blowing my fuses and it ran and drove before i swapped trans case do i swap it back or ????
07-01-2021, 09:33 PM
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None of the above posters have been here in years. It is a 14-year old thread. Check post dates....
