FFG 4x4 Chassis Walkthrough
At a Glance
F100 chassis by Fat Fender shown at the 2026 GNF100 event transforms a 1968 F100 into a modern‑driving truck with real off‑road capability. Built for a Godzilla 7.3L V8 and 10R80 transmission, this chassis is engineered for daily driving, weekend trails, and long‑term reliability. This guide walks through the frame, fuel system, wiring, interior fitment, and supporting components so you can plan your own F100 build with confidence.
What Makes the FFG F100 Chassis Different?
The FFG F100 chassis is engineered specifically for classic Ford trucks—not adapted from another vehicle or pieced together from generic parts. Every mount, bracket, and suspension point is already in the right place, eliminating guesswork and reducing build time.
This chassis is designed for two things: everyday drivability and weekend trail capability. It’s not a show‑only frame. It’s a real‑world platform built to handle modern power, modern suspension, and modern expectations.
- Built in‑house at Fat Fender Garage
- Approximately 6‑month build time
- Ready for the Godzilla 7.3L V8 + 10R80 transmission
- True 4x4 geometry—not just lifted springs
- Pre‑staged mounting points for engine, trans, suspension, and body
The chassis displayed at GNF100 proved how capable the platform is—turning a 1968 F100 short bed into a truck that handles highway speeds, trail climbs, and 400+ horsepower without stress.
How Does a Godzilla Swap Chassis Handle the Engine and Transmission?
The FFG chassis is pre‑engineered for Ford’s 7.3L Godzilla engine and 10R80 10‑speed automatic—the same drivetrain used in modern Super Duty trucks. No cutting, welding, or improvising required.
- Correct engine position for proper driveline angles
- Built‑in transmission crossmember
- Transfer case clearance for 4x4 builds
- Optimized driveshaft angles for reduced vibration
This combo produces ~430 hp and 475 lb‑ft of torque stock, with room for boost later. The 10R80’s deep overdrive keeps highway cruising quiet and efficient.
FFG offers complete Godzilla swap components including motor mounts, oil pans, and accessory drives. Transmission parts are available through the Transmission Components Collection.
What Fuel System Parts Does an F100 4x4 Chassis Need?
Modern engines require steady fuel pressure, clean fuel, and reliable flow. The original F100 fuel system can’t support EFI engines like the Godzilla.
The FFG chassis routes brake and fuel lines inside the frame rails for protection and clean routing.
Fuel Tank
The build used a 30‑gallon Boyd Welding aluminum tank (67‑72 Ford Stealth EFI Tank). It includes internal baffles and an in‑tank pump mount.
Fuel Delivery Parts
- Returnless Fuel Line Hose & Fitting Kit
- Fuel Filter & Mounting Kit
- Fuel Pressure Sensor
- Fuel Pump Relay Kit
- Fuel Line Heat Shielding
Each part matters—modern EFI engines don’t tolerate pressure drops or contamination.
How Do You Wire a Classic Ford Chassis?
The original F100 wiring can’t support modern engine computers, electric pumps, or 10R80 transmission sensors. The FFG wiring approach uses a purpose‑built chassis harness designed specifically for 1967‑72 F‑Series trucks.
- ECU power & grounds
- Fuel pump relay control
- Transmission signal routing
- Sensor inputs (fuel pressure, coolant temp, oil pressure)
- Lighting & accessory circuits
The FFG 1967‑72 Chassis Harness Kit eliminates wiring guesswork and prevents common swap issues like bad grounds or undersized wires.
What Interior Parts Fit the FFG F100 Chassis?
A chassis swap affects cab position, floor height, and interior fitment. The FFG chassis keeps factory body mount geometry so interior parts install correctly.
- Factory seat mount locations
- Correct steering column angle
- Proper pedal assembly position
- Transmission tunnel clearance
Interior parts are available through the F100 Interior Collection.
Builder's Note: The FFG 4x4 chassis isn’t a generic frame swap—it’s a purpose‑built platform engineered for a specific result. When comparing chassis options, ask: Was it designed for your truck and your engine, or does it force you to figure out the details?
Comparison Table
| Approach | Engineering | Wait Time | Engine Support | What You Get |
|---|---|---|---|---|
| FFG 4x4 Chassis | Built for F100 | ~6 months | Godzilla + 10R80 | Modern performance |
| Universal Chassis | Adapted | Varies | Custom mounts | Compromises |
| Modified Stock Frame | Cut & weld | Depends | Limited | Budget‑friendly |
| Crown Vic Swap | Police platform | Quick | 4.6L/5.4L | Good handling |
Does the FFG F100 chassis work for 2WD builds?
Yes—FFG builds both 4x4 and 2WD versions.
Can I run a Coyote instead of a Godzilla?
Yes—the chassis supports both engines.
What comes with the chassis?
Frame, suspension mounts, body mounts. Fuel system, wiring, engine, and interior are purchased separately.
How long does a full chassis upgrade take?
Pro shops: 3–6 months. Home builders: 12–18 months.
Will it work with a long bed?
Yes, but long bed chassis require different frame rails.
Ready to Build Your F100?
Your F100 chassis build starts with us.
Fat Fender Garage exists to redefine the classic vehicle experience. We design and build industry‑leading chassis, interiors, parts, and full builds that merge heritage with innovation.
Comments (1)
I need a 2016 body for kRanch
White pearl brown interior.
Need tailgate