1994 K1500 4.3 to LSX

Hey folks, new guy here. Been lurking for a while, figured I'd sign up and start being active. I've done some research on the LS swaps. I had a '56 Ford with a SBC/Auto and was going to swap a 5.3 EFI in. I researched it thoroughly and was ready to take the plunge, but wound up selling the truck. I have a '53 Chevy car also with an SBC/Auto and considered swapping an LSX into it, but I've decided to sell that car as well.

So I picked up a cheap low mileage 1994 Chevrolet K1500 Reg Cab Long Bed with a 4.3 V6, 5spd, and 4x4. It's really clean, never leaks a drop, drives great. Right now it's my daily driver. I pull a car hauler trailer often, and the truck doesn't have the guts to make for a pleasant haul. It struggles on take-off, up slight grades, and has no passing ability when loaded. So, I figured that as soon as I got my '83 F250 put back together I could haul the trailer with it and have considered swapping an LS into the K1500. Sure I could sell the truck an get something bigger, newer, or whatever, but I got this truck cheap, and I like it. This is a basic work truck that has AC/HEAT and no other options. It came with an AM-only radio. No tilt, no power, nothing extra.

Since I've already bought everything I need to finish my F250, I figure now's the time to start collecting parts for the LSX swap. Once the F250 is done, I'll pull the K1500 into the garage and start the process. I'd like everything to appear as if it came with the 5.3 from the factory. I'm very detailed and take pride in doing a clean job. (My F250 is down for an engine rebuild, but I took it a few steps further and removed all sheetmetal, painted chassis, rebuilt & painted suspension, painted underhood metals, powdercoated core support, etc. Yeah, way overkill):hyper2:

I'll most likely be using a 5.3 engine in the K1500, as they seem readily available for a fair price around here. Here are my questions regarding the swap...

Engine to Trans: Will the 5.3 bolt up to the 1994 NV3500 Transmission? What clutch is required? Any spacers, bushings required?

Engine to Chassis: Are there engine mounts available to allow the engine to bolt to the transmission, keeping the transmission in the stock location (leaving driveshafts alone)?

Engine Wiring: Is there any write-ups or diagrams showing what is required to connect the LS EFI harness to the 1994 truck wiring for a clean factory appearing installation?

Fuel: I gather that I'll need the EFI fuel pump & Vette Filter setup.

Accessories: Will the factory 5.3 accessories clear everything in the engine bay? Will the 5.3 AC Compressor, Alternator, Power Steering Pump work with the 1994 related components?

Radiator: Will the 1994 V6 Radiator work or should it be upgraded to a V8 radiator? What hoses will be required?

I found some local guys advertising that they can swap an 5.3 into any vehicle for $2000 including all parts, computer, harness, mounts, labor. Drive in & drive out. That's not bad, but I figure I can do it myself, save a bunch, and put the savings elsewhere into the truck.

Looking forward to hearing from you folks and learning as much as I can before biting the bullet.

Thanks.

Honestly, you won't save much on that price! Unless those guys skimp like a mother. Are you going to do your own harness? If not, you'll have to pay for a Painless or Nelson harness, and they're $$$! If someone quoted me that price including everything, I'd give them the 2k just so I didn't have to. In the long run, you'll probably be out less money that way. The only problem is that you are as anal about details as some of us around here are, and you'd likely redo it all if you had one stray wire.

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Originally Posted by Astro

Hey folks, new guy here. Been lurking for a while, figured I'd sign up and start being active. I've done some research on the LS swaps. I had a '56 Ford with a SBC/Auto and was going to swap a 5.3 EFI in. I researched it thoroughly and was ready to take the plunge, but wound up selling the truck. I have a '53 Chevy car also with an SBC/Auto and considered swapping an LSX into it, but I've decided to sell that car as well.

So I picked up a cheap low mileage 1994 Chevrolet K1500 Reg Cab Long Bed with a 4.3 V6, 5spd, and 4x4. It's really clean, never leaks a drop, drives great. Right now it's my daily driver. I pull a car hauler trailer often, and the truck doesn't have the guts to make for a pleasant haul. It struggles on take-off, up slight grades, and has no passing ability when loaded. So, I figured that as soon as I got my '83 F250 put back together I could haul the trailer with it and have considered swapping an LS into the K1500. Sure I could sell the truck an get something bigger, newer, or whatever, but I got this truck cheap, and I like it. This is a basic work truck that has AC/HEAT and no other options. It came with an AM-only radio. No tilt, no power, nothing extra.

Since I've already bought everything I need to finish my F250, I figure now's the time to start collecting parts for the LSX swap. Once the F250 is done, I'll pull the K1500 into the garage and start the process. I'd like everything to appear as if it came with the 5.3 from the factory. I'm very detailed and take pride in doing a clean job. (My F250 is down for an engine rebuild, but I took it a few steps further and removed all sheetmetal, painted chassis, rebuilt & painted suspension, painted underhood metals, powdercoated core support, etc. Yeah, way overkill):hyper2:

I'll most likely be using a 5.3 engine in the K1500, as they seem readily available for a fair price around here. Here are my questions regarding the swap...

Engine to Trans: Will the 5.3 bolt up to the 1994 NV3500 Transmission? What clutch is required? Any spacers, bushings required?

Engine to Chassis: Are there engine mounts available to allow the engine to bolt to the transmission, keeping the transmission in the stock location (leaving driveshafts alone)?

Engine Wiring: Is there any write-ups or diagrams showing what is required to connect the LS EFI harness to the 1994 truck wiring for a clean factory appearing installation?

Fuel: I gather that I'll need the EFI fuel pump & Vette Filter setup.

Accessories: Will the factory 5.3 accessories clear everything in the engine bay? Will the 5.3 AC Compressor, Alternator, Power Steering Pump work with the 1994 related components?

Radiator: Will the 1994 V6 Radiator work or should it be upgraded to a V8 radiator? What hoses will be required?

I found some local guys advertising that they can swap an 5.3 into any vehicle for $2000 including all parts, computer, harness, mounts, labor. Drive in & drive out. That's not bad, but I figure I can do it myself, save a bunch, and put the savings elsewhere into the truck.

Looking forward to hearing from you folks and learning as much as I can before biting the bullet.

Thanks.

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hey welcome to the site! im not too familair with the 5 speed in this situation but from what ive read you would use a flywheel from a 4.8. as far as engine mounts dirty dingo mounts are the best. i tried to be cheap and get some ebay adapters for 30 bucks and ended up regreting it. the dirty dingos are adjustable

http://dirtydingo.com/store/product_...oducts_id=1367

as far as the wiring nelson performance can re work the ls harness for 450. then you would have to go through your factory harness and remove everything you dont need. i used www.lt1swap.com to do my own harness and combine it with my factory harness. tons or wiring info there.

with the pre 96 trucks you will need a different fuel pump because the ls engine needs 53psi i believe. warlboro or ac delco has once thats pretty popular. then of course the vette filter is about $50.

all the accessories will work except the a/c compressor. it will not clear the frame rail on the obs trucks. you would have to get an aftermarket a/c bracket or notch the frame. havent seen many people notch the frame so the after market bracket will work better plus with some you can actually reuse your OE r4 a/c compressor. search josh powers and theres a ton of info on a/c bracket options. also kwik and novak make some cool brackets for the a/c.

i would def suggest upgrading your radiator.

IMO 2k for a complete ls swap isnt bad at all. thats about what your probably going to spend anyway. im doing my own right now and even going the cheapo route im over 2k now and still not finished lol.

5.3 usually 500-600
wiring harness -450
fuel sysytem pump fittings and filter 150
motor mounts 130
thats just the basics really. im in cali and they are charging 2500 just for labor if you bring all the parts.

i would also suggest reading over the obs to lsx sticky a couple hundred times. i know i have. since this is your first swap i would suggest reading up on each problem as you encounter it. it took me a few months before i decided i would do it because i was just over loaded with info. so just start off witht he basics and then as you encounter an issue (which you will) someone on here will help you out. ive done my entire swap pretty much by myslef with just the help ive got from this site. good luck
!

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Originally Posted by myzterray

ive done my entire swap pretty much by myslef with just the help ive got from this site. good luck
!

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And yours is coming along very nicely. I've been watching it.

Thanks guys. I'll read up as much as I can. I know $2k ain't bad, but if it isn't done perfectly, I'll throw a fit, so I'll just do it myself. I want to gather as much information as I can for this swap.

I can get an LM7 for about $400 through my connections. This is complete with harness, PCM, and all accessories.

I'm anal about wiring, but I don't have the patience to sort through all the diagrams and what not. Maybe I'll try to find another truck like mine in a junk yard and pluck the harness and I'll give it a try.

I'll look up more info on the 4.8 flywheel to use the NV3500 behind the LM7, thanks for that piece of the puzzle.

I've got a parts list for the LM7 swap I was going to do in my '56 Ford, so I'm familiar with the Walbro pump and Corvette filter. No biggie.

As far as the mounts go, I just didn't want to have to move the transmission forward or backward, resulting in shortening/lengthening the driveshafts, modifying the shifter location, etc. It's not a big deal, I just want to keep that stuff stuck.

Those Dirty Dingo mounts look good. I hadn't thought of slotted mounts. In that case I'll just make my own mounts and save myself $100. I have a CNC Plasma Cutter at my disposal, so that's easy.

One thing I forgot about... I'm wondering if the stock LM7 or other LSx exhaust manifolds will clear the OBS frame/steering? I don't want to have to buy headers unless it's really needed.

Like I said, this thing will be stock besides dual exhaust and some Spin Tech mufflers I've got laying around. Might get a tune, but I don't think I'll need it. I don't plan to drive it hard and risk trashing the NV3500. I just want the extra pulling power when I'm towing, and to pick up a few mpg over the gutless 4.3 V6.

Thanks again

Get a flywheel from a 4.8 and a clutch kit also. And as for the pilot bearing, you can get one for a 2010 ss camaro.

Talk to Chris at LSX Powersports about your wiring harness.......

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Originally Posted by LS3CC

Get a flywheel from a 4.8 and a clutch kit also. And as for the pilot bearing, you can get one for a 2010 ss camaro.

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cheaper option for the corvette fuel filter is Wix #33737 from Amazon.com...approx. $36
Walbro GCA 758 F20000169 255LPH fuel pump is a direct repl. for stock chevy pump for your truck....got mine through Ebay for $98........

If you pick up a 5.3 with a return line on the fuel rail you wouldn't need to do the corvette fuel filter/regulator, it's only a matter of buying the right connections seen here

http://i978.photobucket.com/albums/a...elfittings.png

The rest of your questions have been answered spot on by all the other fellas

Kwik Performance makes access. brackets for swaps...they have a bracket that will allow you to use your orig. A/C pump.....

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Originally Posted by silverado_lover

If you pick up a 5.3 with a return line on the fuel rail you wouldn't need to do the corvette fuel filter/regulator, it's only a matter of buying the right connections seen here

http://i978.photobucket.com/albums/a...elfittings.png

The rest of your questions have been answered spot on by all the other fellas

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lol you love that lil diagram you made huh!

Proud of my mad paint skillz :lol: