1974TORINO

So i'm about to get into my first LS swap. I've got a 66 Ford LTD that I daily and I currently get 10 miles to the gallon on my hopped up 390. The main reason I'm doing this swap is to try and double that mpg, on the highway at least. Later today I'm gonna go look at a Chevy Silverado 1500 from 2000. It's a 5.3l 2wd with 157,000 miles for 2 grand. I hoping to do this swap with everything completely stock from the truck to keep cost down and just get my car running. I plan on using everything like the radiator, ecu, fuel lines, fuel pump, engine trans, accessories, etc. So my question: Is this truck a good donor vehicle idea? Obviously I'll check for condition of all the components the best i can and test drive, but is there any reason to stay away from this year/combo of LS engine and 4l60e, which I assume it has? Also open to any tips/advice on this swap, I've been up all night researching. Thanks everyone.

78TranzAm

If thats the actual mileage thats a great deal. That truck here in Tx would be posted for like $7500 if it only has 150k miles... lol. But you seem to have the right idea as far as using absolutely everything you can from the donor vehicle. Especially since youre putting it in a truck you have the room to use all the stock stuff including the radiator if your core support is long enough. Id even use the stock fan and fan shroud from the truck if possible. Pull the stock harness off and get you a $250 amazon harness with the injector adapters. Then either get a ready to go computer or get yours tuned/deleted for the swap. Also, you could probably run 99-06 long tube headers if you have room on the side of the engine between the wheel wells but im unsure of how your steering linkage is set up and how big your steering box is. But either way, you shouldn't be more than around 3k for your swap, possibly even less if you use the fuel system from the donor too. But id highly recommend running a carfax on it, that way you don't get a 300k mile truck that had the cluster swapped to make people think it only has 150k.

SwapStang

Is the Ford a commuter car or just a fun drive around on the weekend car? The 2k you spend for the truck is just the beginning as anyone that's done a swap will tell you. I would doubt you'd be able to use most of the components and honestly to get everything to fit would require fab work that in the end who knows if it would be worth it rather than just buy new/different stuff... which throws budgets right out the window. If you want cheaper gas mileage for a commuter that 2wd truck is probably 15-17mpg so obviously better and in my opinion a good number for what you'd expect from an LS swap. I think 20mpg from your car with an LS swap would be pretty optimistic. You just have to figure out why you're doing this. If it's just for better gas mileage that wouldn't be enough for me, personally I'd commute in the truck and save yourself a lot of money and work.

ryeguy2006a

iTrader: (27)

SwapStang has some great advice, I was thinking the same thing actually just DD the truck.

If you are bound and determined to LS swap the LTD, that's not a bad price. Keep in mind that you will at minimum need a new oil pan. You won't be able to use the fuel tank, but possibly the fuel pump assembly modified. If not, you need a high pressure fuel pump/tank. Engine mounts can be tricky, so you may need to play around with those to find one that works for you and/or make your own. Also, you'll need to have the ECU tuned and wiring harness modified to run stand alone. You can do the engine harness modifications yourself with LT1swap.com's diagrams and if you are handy with electronics you can use LS Droid to delete the Anti-theft from the vehicle.

LS swaps CAN be done on the cheap, but can also blow your budget out of the water. My advice is to make a plan and budget now, then stick to it. Don't let your project scope creep out of control.

99 Black Bird T/A

iTrader: (4)

Checking VIN and seeing mileage is good advice. A++


I'd get the 390 dialed in right and swap in a Ford automatic overdrive transmission if this is about MPG and budget.

My 72 vette with Dart 400, TH400 3200 stall & 3.08 gear can get 18 mpg highway. I think your Ford 390 can get about 16-17 mpg if the motor is in good condition, carb set up correctly & ignition sorted out with a similar gear.

G Atsma

WAY BACK in the day we had a 1968 Mercury Colony Park wagon with a 390 that got 20mpg on the road consistently. Plus it ran like a striped azz ape.
So good mileage can be had from a 390/C6 in a battleship of a car

pdxmotorhead

Are you running EFI on he 390? A sniper might get you the mileage with less time and work?

I don't think there are any cheap port injection manifolds for a FE but there should be...

1974TORINO

Looks of good advice, thanks everyone. Unfortunately the truck fell through, while it was a believable deal the guy never showed. Back to looking for 5.3s and 4l60es. I could do a lot of work to put efi and overdrive on my 390 but it seems more efficient to grab stuff that is outfitted with those options stock and is proven for many miles, still a toss up on costs. Around here it looks like I could get an engine and trans separately for a grand, then I'd maybe splurge for an aftermarket wiring. I guess that alone adds up to 2 grand ish already. Plus fuel system and what else? Driveshaft and things like oil pan, I hope 3 grand is a good cap on the budget. Also, I'd like to keep rear end gears and tires which are 3.00s and 28inch talls. Rpm calculators say 70 is like 1800 about, is that something that might over-stress the trans?

1974TORINO

Also in that case, any recommendations for an aftermarket wiring harness and where to go from there with a computer? Although it's definitely not the most desirable route, how's the best way to piecemeal together the wiring and computers if I've got non of that to start with? Right now currently looking at an 03 5.3 with no harness (170k on it $350) and then a potentially a 2wd 4l65e(01) or 4l60e(unknown year) either for around $300 but both kind of in "was told it works" condition?

Honestly there's so many options for engines, fewer for trans but oh well, that I'd be ok investing the most in wiring to know that if an engine or trans turns out junk I could more or less just plug in a different one and know that the rest of my systems are solid.

99 Black Bird T/A

iTrader: (4)

Unless your 390 runs poorly or the current transmission toast, I think the bottom end torque will be lacking with a NA 5.3 swap that isn't a direct Injection motor. Loss of 65 cubic inches is quiet a bit.

Swapping I'd try to get the engine, transmission, wiring harness etc all from the same vehicle that you personally verified runs and drives. Piecemeal sets up major risk of being nickeled & dimed to death on the project. It should also reduce the risk of getting junk used up parts, bad engine, or slipping transmission & or failed accessories.

Good luck with project 👍

ryeguy2006a

iTrader: (27)

If you are starting from scratch on wiring, my suggestion would be look at Terminator X Max, so you can control an auto trans. Quite a bit up front, but the wiring is all new and you should be able to get up and running quickly. You'll also need some sort of cooling fan. Either use the stock truck fans which may be difficult depending on where the shroud falls, or buying a efan.

Biggest expenses for LS swaps come from the wiring/tuning, fuel system upgrades, and engine mounts/oil pans/headers. I'd expect to spend around $5k all in for an LS swap. Can it be done cheaper? Absolutely, but you have to do a lot of the work yourself. So if you are handy with wiring and tuning, you can get it done pretty reasonably.

SwapStang

ryeguy2006a and 99 Black Bird T/A and a few others have given invaluable advice about the direction your heading in. You seem pretty intent on swapping this car and if money is no object then by all means I'm in for this build. I love repowering old iron with chevy goodness. However, considering your original post was about gas mileage woes I'd believe money/budget is of concern. This swap could seriously cost anything depending on how handy you are or are not. Yeah you could get a motor and tranny for under 1k bucks the rest of this stuff can and most likely will spiral out of control if you aren't really careful at planning your build and being pretty resourceful. The holley wiring that was suggested is in the $1400 range. Now unless your sticking with a stock truck manifold and injectors get the wallet back out and cough up for that. Lets just throw a number of $3000 to $5000 to finish this swap. High? Maybe. It's been said before yes it can be done cheaper if your willing to put in the time and research. I don't recall you answering what exactly this car's purpose is. Is it a daily driver? Show car? Weekend car? That for me would determine the route I'd be taking. It also would make me wonder if for $1000 to $2000 you could maybe make that 390 be closer to your goals. A swap isn't an easy task and someone mentioned it's something many start and few finish. It's real easy to lose sight of the end and get caught in limbo.
I'm definitely not trying to talk you out of it just trying to make you well aware that budgets can be tough to stick to, especially for a first time swapper with a car that isn't typically done and buying parts a-la-cart. Everyone here will help you as best we can if you go forward with it but definitely explore/consider a few options before you start buying swap parts. Just my .02. Good luck!

1974TORINO

I'm thinking the gear ratios in 4l60e with make up for the loss of power, my 390 has a 3 speed c6 with a 2.42 first gear. But even if i did loose power it's the gain in fuel economy + overdrive + parts availability i'd like.

1974TORINO

I'm pretty confident in being able to get most stuff done myself, resourcefully. Definitely the least confident in being able to correctly set up an ecu, or having it sent out, so that's where I'd like to put money into the electronics

1974TORINO

Yea I definitely understand that this isn't the most practical, so I guess it comes down to figuring out what scenario I'll be most happy with in the end, I look forward to the challenge of this too. I've done engine swaps before but never anything that wasn't carbureted, the most EFI I ever messed with was an 86 BMW. The car is gonna be a daily all the way. I have considered adapting a 4l60e, maybe EFI, to my 390, get the overdrive and low 1st gear that I want, but again adapting anything is pricey enough to match LS swap costs almost. I do suppose that if i didn't reach my goal of doubling my fuel economy, which would be mean 18-20 mpg with the LS, I would be disappointed. That seems reasonable though from other forums.

1974TORINO

Just inquiring again, would there be any issues pulling 70mph at 1800 rpm through a 4l60e? I know overdrive gears can be pretty weak and can be loaded up too much if you're not careful, or there can be problems with converter stall causing heat.

G Atsma

Weak overdrive gears are one of the reasons you will almost never be in that gear under full throttle.
Floor it, it WILL shift down regardless of speed, and stay there until you lift.

1974TORINO

Sorry I guess I don’t mean “pulling” at 70, but cruising there at that low an rpm will be ok?

1974TORINO

Found a 4l65e in town for $300 from an 05 silverado with 120k. I think I'll jump on it, good resale value and could adapt it to my 390 with an available kit if I change my mind on the rest of the swap.

G Atsma

NO problem.