Junkyard LS swap

Greg

Make RME Rockcrawling Again!
Admin
Often you hear about how cheap a LS swap is... I thought this would be worth putting together and adding up the costs, for the sake of sharing on here. There are a LOT of options and the total cost really depends on what you want in the end, how far into the engine you go, what it's going into and what you start out with. I've done a handful of LS swaps at this point, but I'm far from an expert. If you see anything I missed, feel free to mention it!

My plan is to swap a stock 5.3 into the 1967 Pontiac Bonneville, so that will be my example for this thread. The vehicle really doesn't matter, but it may make a difference in cost at the end of the day.

For this specific build, I'm going to try to keep it cheap and track the needed parts and costs. I'm starting with a 2002 Gen III 5.3 LM7 with 130k miles on it. These are probably the most common LS truck engines, Iron block, aluminum cathedral port heads, factory roller cam, truck intake, etc. A 4.8 (LR4) is similar and should be priced a bit less due to the displacement, but they do have a flat-top piston for higher compression, making the HP & TQ loss pretty minimal. Both of these small truck engines are pretty prevalent, but nearing 20 years old they may be hard to find with low-ish miles. It's best for cost if you can find a good running engine that you don't need to tear down, rebuild, etc. Even minor upgrades can add up fast, cam shaft upgrades are nice and you'll see big gains, but not cheap.

The best thing you can do is purchase a complete engine with all the accessories & mounting brackets; starter, alternator, water pump, intake, coils, throttle body & injectors, etc. I was able to get the ECU & engine cover in addition to all the accessories.... all for $600. (My coils had broken connectors due to a sloppy removal, so I'll have to replace those.) I was able to use a Hotsy pressure washer to degrease the 5.3 before the hard work of swapping it into the car.

$600 seems to be a decent price these days, I can find 4.8's for $500 from local wrecking yards. The price seems to jump up from there, depending on where you look. (Many years ago when I built the RME TJ around 2008, I used a low-mile take-out LM7 that was only a few years old and paid $1200.) I've built a L33 5.3 for my '66 El Camino with a brand new block and that build nickle & dime'd me, big time. It was nice knowing it was all fresh, but it wasn't cheap in the end.

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The oil in this 5.3 looks great, always good to see with a used engine!

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Engine management system (wiring harness & ECU; If you can get a good factory harness and you're motivated, you can trim it down to run standalone. I prefer buying a aftermarket harness. You can find pretty cheap Chinese wiring harnesses as low as $120, but the quality is questionable, plugs are often wrong or wired backwards, etc. There are other better options in the $300 range, but you need to make sure they have the options you need. Including the fuel pump and cooling fan fuses & relays are a big part of that, the additional costs add up quickly. You'll need a factory ECU with some changes to make it run. Using HP Tuners or similar, you or a tuner will need to remove VATS (anti-theft) at a minimum, delete 2 of the 4 O2 sensors, etc. High quality harnesses cost around $500-600, a deleted ECU usually costs around $200. I'm considering a middle of the road harness from Speedway Motors at $350, with no fan relay. I have HP Tuners and after buying a $100 credit, I can tweak the ECU to my needs.

Transmission options; Depending on your needs & build, the modern electronic controlled transmission can be used with the factory ECU controlling the functions of the trans. I'm hoping to find a good, used 4L60E transmission for this swap. Hoping to be into the transmission around $500, we will see.

Exhaust; Factory exhaust manifolds on LS engines actually perform pretty well, I've used shorty headers in the past and they work, but I don't know that you really gain anything, more than looks. I have a set of shorty headers that I'll probably run with this swap if they fit, only because I have them. I paid $150 for the knock-off shorty headers. I'll probably build my own exhaust from there.

Radiator & Cooling Fan; Upgrading the radiator is always wise if you're swapping in a V8, my car didsn't have a radiator with it and while I got the factory radiator from the Tahoe my engine came out of, it won't fit under the hood. I'll be looking for an aftermarket radiator for the car. Along with the radiator, you'll need to consider transmission cooling. Looks like aluminum options that fit my car are in the $250 range.

Fuel Pump & Regulator; In tank pumps are more reliable, with the gas keeping the pump cool over time. Using a Corvette fuel filter & regulator is an affordable & simple way to make sure the fuel pressure is maintained consistently. For my build, I'm hoping to find a factory fuel tank, probably from a GM truck and be able to use the factory sending unit, fuel pump, etc. Hoping to find a tank, sending unit & pump for around $100.

Oil Pan; The truck oil pans are quite deep and cause fitment problems in most anything other than a tall truck. The most common upgrade is a LS1 oil pan from a F-Body Camaro, or you can upgrade to a aftermarket pan like a Holley or something similar. These usually run around $500. I found a similar pan to the Holley (probably a Chinese duplicate) for $220 on Amazon. It's a copy of the 302-3 and should work for a 1967 GM B-Body.


I'll update this thread as the swap continues... :D
 

Pile of parts

Well-Known Member
Location
South Jordan
Excellent topic, and one that I always think I can do fairly inexpensively, only to find how much I get nickle and dimed by the end.

I think your basis gives a good average. My opinion is that it's always better to start with a complete donor vehicle. That way you can get a much better idea on condition if the drivetrain, have all the misc. parts, recoup costs in parting out/scrap, etc. I ended up at about $300 for the cost of the drivetrain in my last swap, by the time I sold a few parts, scrapped the cats and scrapped the rest. I kept the transmission, but haven't used it, so that could have gotten me even closer to breaking even on the drivetrain purchase. The sum of the rest of the parts is a different story.💰💰💰

Due to a deadline for my swap I did order (and use) an Amazon/Chinese harness. I had full intention to thin out my factory harness but ordered the Amazon as a back up. I have to say that overall I was impressed with the quality. Fortunately, there is enough information online about them and the common problems so I was able to perform a series of tests before installation. You're correct in your statement about mismatched connections. Due to so many variations of the LS engines, you'd have to make sure you knew every type of connection you needed. I didn't so I ended up splicing injector, O2 and MAF connectors from my factory harness to the Amazon harness. That may have been more my mistake than Amazon's.

Anyway, I'll look forward to reading your doccumentation of expenses. I tried to not keep track of mine and just get it done. I do have a rough idea and it's not as cheap as I thought it would be.
 

85CUCVKRAWLER

Active Member
Location
Tooele
You should consider BP automotive for you harness. They are high quality and affordable.

As far as flashing goes, you can use Ebay for this or find someone local who has the program.
 

NYCEGUY01

Well-Known Member
Location
Willard, UT
My c10 is running a harness from Wayne at 150tunes.com.
All new hi quality wire with the fabric wrap etc...
He was also able to do a couple custom things I needed added like the cruise control wires and where they ran in the harness etc..
Longer MAF lead etc...
I believe they are $500 total.
Its got to be a huge upgrade from the generic speedway/amazon harnesses.

I seem to have been converted to Holley stuff these days, Im running a Terminator Max in the Rambler project right now. Depending on the project a stock ECM with OBD2 is pretty nice though. My C10 had Dakota gauges and just plugging in to the OBD port and having the dash work was nice..lol


If you have good hood clearance, I'm guessing you have a ton, look into Tejas steelworks motor mounts. They are made for C10 trucks but they move the motor up and forward a few inches which in alot of the GM chassis's solves alot of issues like the oil pan clearance, AC compressor fitment, driveline angle and so on....

Such a cool car man...
Get it running and moving by the end of september and make the drive to Tuscon with us for the Duct Tape Drags.
Its a great time and this car will fit right in...
 

UNSTUCK

But stuck more often.
I posted a pic the other day of the LQ9 I just tore down. We went a little different route and I wouldn’t call it budget, but am trying to do it cost effectively. We bought the whole running Cadi at an auction for $1800. 195k mikes. The transmission has fresh paint and red atf so I believe it’s a recent rebuild. That has changed my tcase plans since I don’t want to tear the trans down.

The engine block looked great and my simple measurements show it should just need a hone job and the heads resealed. That quote was $800 and if further machining is needed it will go up to around $1200. I have about $1100 in a Texas Speed shopping cart with a truck cam, springs, lifters, trunnions, etc. I’ll probably build the same cart at Summit and get things cheaper.

I found a dyno tuner here that will do a base tune to get it running and then spend an hour on his dyno to dial it in. All for $650. That seemed reasonable to me and we’ll probably go that route.

We sold the Cadi to a junkyard yesterday for $400 after stripping it pretty bare.
 
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