close to starting my Nova LS swap need opinions
#1
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I am a few days from starting my swap from a 350 sbc to a 4.8. I have almost nothing in the car and engine. I do have the computer and the modified harness ready to go but im still debating on cpu or carb. Id love to hear thoughts good or bad on both. Im going to post my progress as I go. Thanks to anyone who wants to chime in. Here are pics as she sits. Like I said im a couple few days of cleaning and coating from the start.
#2
TECH Fanatic
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It cost relatively the same to do either the carb is not cheaper as you have to buy intake, ignition, fuel pump, controller and carb. .
And since you already have the harness run the EFI.
But it's your car if you want a carb run it!
And since you already have the harness run the EFI.
But it's your car if you want a carb run it!
#3
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The car is a 73 with a manual 4 speed. Its a pretty solid car that I was actually about to paint and decided that since the engine was out to restore the compartment why not sell the sbc. Lol!! Now im comitted and excited about it. I dont want to sink a huge amount of money into it as its not the car of my drems but will be a fun driver.
#5
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I see you have a 71 Nova swap in progress. What pan are you using? I'm considering cutting the stock truck pan down but not sure if it actually works in the end. Also if anyone has any knowledge on this idea... A buddy have me a set of motor mounts to swap an ls into a truck. If I tried to use them I would obviously have to change the mount on my frame as these are not nearly as wide as the ones in my car. Would doing this sit.the engine up at all possibly giving a little more room underneath? Just an idea??
#6
TECH Senior Member
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I have the Retro-LSx pan which was the prototype and is now the Holley pan. Check one of the other Nova swap threads, he has been doing a lot of research and posting on trying to cut down one of the Truck pans. Many have cut the pan, but you have to be aware that you will lose oil capacity and possible the oil baffles.
As far as the adapter plates, they should work ok if you use both the engine mounts and the frame stands and that they can bolt up to the plate (pretty sure they can). But not knowing what they look like, it would be hard to say what the engine would end up being position at (low/high, forward or back). You could always modify or build new frame stands for the crossmember to match up with the engine mounts and adapter plates. Post some picture of what you have.
BC
As far as the adapter plates, they should work ok if you use both the engine mounts and the frame stands and that they can bolt up to the plate (pretty sure they can). But not knowing what they look like, it would be hard to say what the engine would end up being position at (low/high, forward or back). You could always modify or build new frame stands for the crossmember to match up with the engine mounts and adapter plates. Post some picture of what you have.
BC
#7
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An overdrive trans will make a bigger difference in drivability then EFI or carb. But I understand budgets.
EFI will run better in the cold and overall be less hands on. Carbs are more for guys who like to tinker. Once you get the carb set they can be pretty maintenance free, but getting there can take some effort initially.
Gas mileage will be the same for either carb or EFI. EFI guys don't like to admit that but lots of people posting real world numbers says otherwise. With a non-overdrive trans MPG probably isn't on the top of your list anyway.
Cost can swing either way depending on what you are starting with. If you go EFI don't forget the price of a tune every time you make a big change or the $$ for tuning software and all the time it takes to learn it. Also EFI really needs a sumped tank. Cost of the fuel pump and lines affects both swaps so doesn't matter. LS carb intakes and ignitions are starting to show up used, and of course you can pick up a used carb dirt cheap. All it takes is a failed MAF or computer and the carb will start looking way cheaper.
Carbs will be massively cheaper to upgrade or to swap to a different vehicle.
Finally carbs and carb intakes make more HP than EFI. You lose a little in the mid band, but with just a straight carb swap you pick up HP on both the upper and lower ends.
If all you want to do is cruise or if you drive a lot in cold weather, then you will probably be happier with EFI.
EFI will run better in the cold and overall be less hands on. Carbs are more for guys who like to tinker. Once you get the carb set they can be pretty maintenance free, but getting there can take some effort initially.
Gas mileage will be the same for either carb or EFI. EFI guys don't like to admit that but lots of people posting real world numbers says otherwise. With a non-overdrive trans MPG probably isn't on the top of your list anyway.
Cost can swing either way depending on what you are starting with. If you go EFI don't forget the price of a tune every time you make a big change or the $$ for tuning software and all the time it takes to learn it. Also EFI really needs a sumped tank. Cost of the fuel pump and lines affects both swaps so doesn't matter. LS carb intakes and ignitions are starting to show up used, and of course you can pick up a used carb dirt cheap. All it takes is a failed MAF or computer and the carb will start looking way cheaper.
Carbs will be massively cheaper to upgrade or to swap to a different vehicle.
Finally carbs and carb intakes make more HP than EFI. You lose a little in the mid band, but with just a straight carb swap you pick up HP on both the upper and lower ends.
If all you want to do is cruise or if you drive a lot in cold weather, then you will probably be happier with EFI.
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#8
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Go EFI and do not look back.
I almost guarantee once you drive the car for a year, you are going to want to turbo it.
Having EFI right off the bat will help you get great MPG, better performance and easier upgrades as the car evolves through the years.
check out my build for ideas if you would like.
I almost guarantee once you drive the car for a year, you are going to want to turbo it.
Having EFI right off the bat will help you get great MPG, better performance and easier upgrades as the car evolves through the years.
check out my build for ideas if you would like.
#9
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The car is nothing more than a toy so fuel mileage is not a concern at all. I have kicked the idea of a turbo later on but im not ready to tackle that yet. Im leaning towards the computer and setting it up as a stand alone. My initial thoughts are to get it running as a basic stock setup with an ls1 intake. Once its running a cam swap would be the first thing I do. I would like to keep the 4 speed in it as I have loved the idea of an ls hooked up to it. Plus with the engine being shorter stroked the power will be in the higher rpms anyways. I do have an edelbrok pump in a box laying here #350-17933. not sure if I could make thatbwork for this or not but it would be nice. I appreciate all of the input im receiving here!! This site is nothing short of Amazing!!!
#12
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Efi it is!! I'm going to spend a day with POR 15 and will be dropping the engine down this weekend. I am kind of down on doing all of this work to put the 4.8 in but I literally have $50 in the engine, harness and computer. Got the engine out of a friends smashed truck with everything for $400 and sold the 350 for $350.
#13
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But i wouldnt use those motor mounts, those are like 6.00 at autozone and will not hold up long term with an engine with power without a turnbuckle or torque chain on it.
energy poly mounts is what is normally used.
#15
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Yeah that will work but you will have to make your own frame stands or buy the stock ones from year one or something like that. Your car has the newer clamshells which will also work, Just bolt up your old engine motor mount brackets off the engine onto the adapter plates.
But i wouldnt use those motor mounts, those are like 6.00 at autozone and will not hold up long term with an engine with power without a turnbuckle or torque chain on it.
energy poly mounts is what is normally used.
But i wouldnt use those motor mounts, those are like 6.00 at autozone and will not hold up long term with an engine with power without a turnbuckle or torque chain on it.
energy poly mounts is what is normally used.
#16
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Either way i would suggest upgrading to better mounts. Poly mounts either clamshell. which is what is still bolted to the car or the perch style.
I removed my factory clamshell mounts and use a set of energy perch style mounts and custom made perches on my frame so i could put the engine wherever i wanted to make room for everything.
Its all on how you want to do your car.
#18
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The mounts I have are sold by jegs.I want to say they are Trans Dapt. I'm at work and can't look? They feel almost like a rubber, is that what you're saying I need for th mounts on the frame? And I do.have the plates they mounts Bolton just didn't think to take a pic