Uploaded August 2026 | Updated September 2026, 1 day ago
We're finishing up this custom JK before it heads to the Great Smoky Mountain Jeep Invasion. Adam walks through why we use a tube chassis, how it changes the suspension geometry and clearance compared to a factory Jeep frame, and some of the details we've developed after building several of these JKs.
This build combines an LS 427, 4L80E, Atlas transfer case, Crane 14-bolt axles, Magnum knuckles, RCV axle shafts, Wilwood brakes, coilovers and bypass shocks with a true four-link suspension capable of 14 inches of shock travel front and rear.
We also show some of the less obvious details that make a complete build work: our 31-inch cooling package, Hydroboost and ARB mounting, steel rear inner fenders, low-mount 20-gallon fuel cell, body armor, storage, and the small fabricated pieces that finish the JK as a complete system.
Then it's time for first startup—and this one doesn't go perfectly.
Follow along as we work through a starter problem, diagnose an incorrect oil-pressure reading, and continue the final system checks before this Jeep has to be loaded for the show.
That's part of building a custom vehicle. The goal isn't to never run into a problem. It's to know how to work through it.
Timestamps
00:25 Custom Jeep JK tube chassis overview
00:35 LS 427, 4L80E, Atlas & Crane 14-bolt drivetrain
01:14 Why build a JK on a complete tube chassis?
01:46 Clearance, 14" shocks & suspension travel
02:04 Setting up ride height for crawling vs. faster terrain
02:19 31" radiator & cooling system
02:29 Coilovers, bypass shocks & Hydroboost brakes
02:34 WOD Hydroboost, steering column & ARB mounting
03:15 Custom JK body armor & doors
03:36 Rear inner fenders & inboard shock packaging
04:01 20-gallon low-mount fuel cell & rear storage
04:17 Finishing details & body/chassis packaging
04:53 Loading the Holley EFI startup tune
05:49 How we approach the first engine startup
06:21 First system check: fuel pump & oil pressure
07:01 Troubleshooting the no-crank problem
09:02 Finding the starter interference problem
09:35 Round two: first fire
10:04 Diagnosing the oil-pressure sensor reading
10:50 Successful startup & next steps
11:58 Final system checks before Jeep Invasion
12:28 Heading to the Great Smoky Mountain Jeep Invasion
Learn more about Wide Open Design Jeep tube chassis, complete builds, fabrication components, and off-road builder parts at WideOpenDesign.com.
#WideOpenDesign #JeepJK #JeepBuild #TubeChassis #JeepTubeChassis #RockCrawler #RockCrawling #OffRoadFabrication #CustomJeep #LSswap #LS427 #FourLink #OffRoadBuild #JeepWrangler #CraneAxle #HolleyEFI
We're finishing up this custom JK before it heads to the Great Smoky Mountain Jeep Invasion. Adam walks through why we use a tube chassis, how it changes the suspension geometry and clearance compared to a factory Jeep frame, and some of the details we've developed after building several of these JKs.
This build combines an LS 427, 4L80E, Atlas transfer case, Crane 14-bolt axles, Magnum knuckles, RCV axle shafts, Wilwood brakes, coilovers and bypass shocks with a true four-link suspension capable of 14 inches of shock travel front and rear.
We also show some of the less obvious details that make a complete build work: our 31-inch cooling package, Hydroboost and ARB mounting, steel rear inner fenders, low-mount 20-gallon fuel cell, body armor, storage, and the small fabricated pieces that finish the JK as a complete system.
Then it's time for first startup—and this one doesn't go perfectly.
Follow along as we work through a starter problem, diagnose an incorrect oil-pressure reading, and continue the final system checks before this Jeep has to be loaded for the show.
That's part of building a custom vehicle. The goal isn't to never run into a problem. It's to know how to work through it.
Timestamps
00:25 Custom Jeep JK tube chassis overview
00:35 LS 427, 4L80E, Atlas & Crane 14-bolt drivetrain
01:14 Why build a JK on a complete tube chassis?
01:46 Clearance, 14" shocks & suspension travel
02:04 Setting up ride height for crawling vs. faster terrain
02:19 31" radiator & cooling system
02:29 Coilovers, bypass shocks & Hydroboost brakes
02:34 WOD Hydroboost, steering column & ARB mounting
03:15 Custom JK body armor & doors
03:36 Rear inner fenders & inboard shock packaging
04:01 20-gallon low-mount fuel cell & rear storage
04:17 Finishing details & body/chassis packaging
04:53 Loading the Holley EFI startup tune
05:49 How we approach the first engine startup
06:21 First system check: fuel pump & oil pressure
07:01 Troubleshooting the no-crank problem
09:02 Finding the starter interference problem
09:35 Round two: first fire
10:04 Diagnosing the oil-pressure sensor reading
10:50 Successful startup & next steps
11:58 Final system checks before Jeep Invasion
12:28 Heading to the Great Smoky Mountain Jeep Invasion
Learn more about Wide Open Design Jeep tube chassis, complete builds, fabrication components, and off-road builder parts at WideOpenDesign.com.
#WideOpenDesign #JeepJK #JeepBuild #TubeChassis #JeepTubeChassis #RockCrawler #RockCrawling #OffRoadFabrication #CustomJeep #LSswap #LS427 #FourLink #OffRoadBuild #JeepWrangler #CraneAxle #HolleyEFI
