LS 6.0 Swap

[Black Beauty]

So I’m thinking about ditching the goodwrench 350 I’ve got in my 85 k20. Seen about 20 hours worth of YouTube’s and read a few forums on people who’ve done swaps. I’m not looking to get maximum power or anything crazy honestly just want the 2500 engine in my old 2500 truck.

I’ve seen what I think to be are decent deals online for engines for about $12-1600 for a pullout motor with 180k miles or so. I would prefer to have something around the 130-150k range. My idea and goal is to drop it in and drive away. I don’t want to rebuild it(yet) just want something more reliable than what I’ve got now.

I know that I’ll need the following;

Electronic fuel system
New engine mounts
Adapter kit for trans(tb400)
Stand alone harness And Ecu

I want to get a cooling system that’ll keep up with the new ls vs the old one, and what do I need to do without spending $1k on a new gauge cluster?


Is there anything I am missing? And what kind of pitfalls should I be aware of. Got a buddy who’s done a few but I like to arm myself with as much knowledge as I can. Thanks!


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[eskimomann209]

I used the Squarebody radiator. Pretty easy and mine was fine. Also used the electric fans ran by the ecu keeps it pretty cool. I’m using the 90-91 suburban cluster. It has the VSS and everything else works with our trucks. I went with the 5.3 for MPGs

 

[Camar068]

one of the best things to do is to start a spreadsheet in excel with everything you know you need with part #'s, sources, and prices.

-There are plenty of threads in here with cooling fans that will work with your stock radiator. Get the relay box from the vehicle you engine comes out of. Then it's a simple hook up input signals and output to the fans....done

-you'll use a camaro (forget what year) sensor for the temp as it's 3 wire for your stock gauge and to the ECM....ACDELCO 12551708.

-there's a small adapter needed for oil pressure so you can use your existing type sending unit, about $10-20.

-the truck already has a neutral safety switch built into it, save yourself the time and utilize it.

-get your plugs n wires from rockauto (we get a discount here)....their price will beat anything local...allowing you to upgrade a bit for the same price

-you'll see corvette fuel pressure regulator/filter used a lot.....WIX 33737

-use a '87+ sender and replace the pump with ACDELCO EP381 (again used a lot by those that've done it). You probably want to replace the tank with one that has baffles in it. Might be a good time to do the 'burb tank under the bed (only about $10 difference in price between saddle and burb tanks....RockAuto).

-wiring harness (3 options) 1. do it yourself, 2. pay someone to do yours (normally includes the ECM reflash) for ~$250 locally (should include relays wired in), or 3. pay $600+ for a harness online.

-figure out how your going to get a VSS (speed) signal to the ECM. I don't know about TH400's. Google's your friend.

Just a few things to think about that I saw by just glancing at my spreadsheet. Highly recommend starting a spreadsheet for your future reference during the build....and years after when you need to replace that part.

 

[Black Beauty]

Camar068 thanks for the good info. I agree a spreadsheet is a good idea. I’ll start one for sure. Appreciate your help


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[RoryH19]

A lot of good advise above.
I'd say find a 2500 donor, gen 3 ls or 4 but that will cost more.
Take everything from the radiator to the transfer case.
They will typically be 6.0/4l80e.
Buy a 241c transfer case from a 90 or 91 3/4 ton suburban or 4 door square. This will give the the vss and the higher spline count of the 4l80e. It will be right hand drop. Also take the gauge cluster.
I run the donors dual electric fans.
See my thread for more info.
I also have a spreadsheet with around 8 tabs.

While you have the engine, trans and t-case out replace the seals throughout. Takes more time but well worth it.

Good luck.