K5 ls swap

Gervais · Mar 17, 2026

Hey guys I’m new to the forum so bear with me. I have a 85 k5 blazer I was using for a mud truck. I have a 06 Tahoe and would like to install the engine in the k5. Looking for a list of what parts and stuff I need to do the swap and where everyone is purchasing. Also should I keep the original transmission in the k5 or should I use the 4l60 from the 06 Tahoe. Any help would be greatly appreciated. Thanks in advance

Ricko1966 · Mar 17, 2026

Is the Tahoe 4wd?

Gervais · Mar 17, 2026

Yes sorry I forgot to mention it was 4wd

TotalyHucked · Mar 18, 2026

If you're on Facebook, join the "LS and LT Swapped Square Body GM Trucks" page and check out the files. Lots of good info there. Scotty Baccus runs the page and also owns Tejas Steelworks, they sell the mounts/transmission mounts/fan shrouds/etc to do the swap.

I used his engine mounts/trans mount/fan shroud on my truck and they're all top notch parts. I haven't done a 4x4 but there's lots of good info on that page for them. Scotty's a good dude that's very willing to help. I would highly suggest using the 4L60 out of the donor as well, half the reason for the swap is to gain OD (or if you have a 700R4, to get rid of that TV cable setup that's so easy to adjust wrong and burn up a trans). Plus, there's no real good way to adapt the TV cable of the 700 to a modern throttle body that I'm aware of.

Speed engineering 1 3/4" headers are the go to as well. Custom driveshafts. You'll likely need an adapter to hand the K5's transfer case off the 4L60.

For a harness, I'd either do BP Automotive or a Holley Terminator setup.

Camar068 · Mar 18, 2026

For the VSS signal, I drilled/tapped the 4l60e adapter to accept a camaro speed sensor. On the output shaft, they make clamp on reluctor wheels. Sample below....I'm sure you can get the sensor and reluctor cheaper than the link below.

Clamp reluctor wheel

89Suburban · Mar 18, 2026

Gervais said:
Hey guys I’m new to the forum so bear with me. I have a 85 k5 blazer I was using for a mud truck. I have a 06 Tahoe and would like to install the engine in the k5. Looking for a list of what parts and stuff I need to do the swap and where everyone is purchasing. Also should I keep the original transmission in the k5 or should I use the 4l60 from the 06 Tahoe. Any help would be greatly appreciated. Thanks in advance

Where did you mud race at? I used to run a Suburban at Muddy Run Raceway in Madera, Pa back in the late 90's.

vr1967 · Mar 18, 2026

Gervais · Mar 18, 2026

Thanks guys. I do have facebook and I will definitely look into that page. I was running it at a couple local mud pits in ny but looking look one is shutting down. But there is another that runs multiple events which isn’t far away which is stuck in the muck. I need to do some gearing after the swap it’s definitely too high for the mud. I’ll probably just run stacks again on the ls for as long as it’s in the mud. Appreciate the help guys. From what I gather I definitely need the engine mounts wiring harness exhaust to start. Like I said it’s a mud rig for now so I don’t want to get too involved as it won’t be street driven. Atleast not now like I used to.

Craig Nedrow · Mar 23, 2026

TotalyHucked said:
If you're on Facebook, join the "LS and LT Swapped Square Body GM Trucks" page and check out the files. Lots of good info there. Scotty Baccus runs the page and also owns Tejas Steelworks, they sell the mounts/transmission mounts/fan shrouds/etc to do the swap.

I used his engine mounts/trans mount/fan shroud on my truck and they're all top notch parts. I haven't done a 4x4 but there's lots of good info on that page for them. Scotty's a good dude that's very willing to help. I would highly suggest using the 4L60 out of the donor as well, half the reason for the swap is to gain OD (or if you have a 700R4, to get rid of that TV cable setup that's so easy to adjust wrong and burn up a trans). Plus, there's no real good way to adapt the TV cable of the 700 to a modern throttle body that I'm aware of.

Speed engineering 1 3/4" headers are the go to as well. Custom driveshafts. You'll likely need an adapter to hand the K5's transfer case off the 4L60.

For a harness, I'd either do BP Automotive or a Holley Terminator setup.

Thanks Hucked for this info, will use it on the Nova LS swap.

jcperformance · Mar 23, 2026

Good swap choice For a 5.3 LS from the ’06 Tahoe you’ll need at minimum: wiring harness + PCM (reworked), fuel system upgrade (high-pressure pump + return/regulator), motor mounts, LS swap oil pan (truck pan won’t clear), exhaust, cooling setup, and driveshaft mods.

Blazerbiker · Mar 23, 2026

One thing to consider for your use is a lot of swap crossmember and motor mount systems are pretty light duty which is often (probably usually) fine in 2wd/street use but offroad is a different story. Shameless self promotion here: we (ORD) have a crossmember and motor mount system that is well proven to keep things in place in heavy use. Well worth your time to check it out.

Camar068 · Apr 1, 2026

Blazerbiker said:
One thing to consider for your use is a lot of swap crossmember and motor mount systems are pretty light duty which is often (probably usually) fine in 2wd/street use but offroad is a different story. Shameless self promotion here: we (ORD) have a crossmember and motor mount system that is well proven to keep things in place in heavy use. Well worth your time to check it out.

Shameless ask for said promotion (lol)....make a front cross member (4WD under radiator).

[edit] sorry didn't mean to come across bashing ....wishful thinkin' lol.

sorry to jack op a bit.

K5 ls swap

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