I Put a Mustang S550 IRS in My 1959 GMC Apache!

Today we're taking the 1959 GMC Apache / GMC 100 build to another level! I'm finally starting the independent rear suspension (IRS) swap I've been planning for this truck. The entire stock rear suspension comes out, and I'm mocking up the IRS directly under the chassis to figure out exactly where everything needs to sit. I'm using a laser level, digital level, measurements, bolts, brackets, and fabrication to get the IRS centered and squared up. The goal is to get this truck LOW while keeping the suspension functional. After bolting the IRS in, the chassis dropped several inches from where it originally sat — and now I'm starting to question whether coilovers are really the way to go or if this truck is trying to tell me to put AIRBAGS on it! This is a completely custom setup. There isn't a bolt-on bracket kit for exactly what I'm doing, so I'm figuring it out here in the garage at Spanky's Corner. In this episode: Removing the stock rear end Preparing the chassis for IRS Mocking up the independent rear suspension Centering and squaring the IRS Using a laser level and digital level Measuring ride height Fabricating temporary mounts Cutting the old suspension mounts off Testing how low the chassis will sit IRS suspension travel Coilovers vs airbags Getting ready for the permanent IRS mounts Preparing for the front suspension upgrade This is only Part 1. Once the permanent brackets arrive, we'll finish mounting the IRS and then move on to the front suspension. 👇 COMMENT BELOW: Would you run COILOVERS or AIRBAGS on this truck? And don't forget to LIKE, SUBSCRIBE & FOLLOW THE BUILD because this GMC Apache is just getting started! #GMC #GMC100 #GMC101 #GMCTruck #GMCApache #ApacheTruck #IRS #IndependentRearSuspension #TruckBuild #ClassicTruck #ProjectTruck #CustomTruck #Suspension #TruckFabrication #SpankysCorner ⏱️ YouTube Chapters 00:00 Starting the IRS Swap 00:46 Pulling the Bed & Stripping the Rear 01:05 Leveling the Chassis 01:43 How Low Do I Want This Truck? 02:27 Everything Is Custom 03:16 Working on the Truck Alone 04:40 Removing the Stock Rear End 06:56 The Rear End Is Out! 07:11 First IRS Mockup 08:02 Checking Ride Height 08:37 Moving the IRS Forward 10:00 Using a Laser Level 11:00 Finding Center 12:00 Measuring the Chassis 13:00 Centering the IRS 15:24 Drilling the Temporary Mounts 15:57 Getting the Hardware 17:08 Dropping the Chassis on the IRS 18:00 Making the IRS Hold 19:01 It's Sitting on Its Own! 20:10 Leveling the IRS 21:08 Measuring for the Brackets 22:16 Fabricating Temporary Supports 23:03 The IRS Is Holding! 24:00 Testing Suspension Travel 24:45 Measuring the New Ride Height 26:04 Removing the Last Block 26:37 IRS Finally Hits the Ground 27:07 The Truck Dropped 5+ Inches! 27:51 Look How Low It Sits 28:02 IRS Mockup Is Complete 29:26 Look How Low It Goes! 30:21 Coilovers or AIRBAGS? 31:21 Day 2: More IRS Fabrication 31:34 Plasma Cutter Time 32:04 Cutting the Old Mounts 32:43 This Plasma Cutter Is AWESOME! 33:26 Part 2 Coming Soon 🔑 YouTube Tags 1959 GMC Apache, 1959 GMC truck, GMC Apache build, GMC 100, GMC 101, GMC truck build, GMC truck restoration