Trail Build Recipe — 35s, Dana 44 Lockers, 4" Lift

Difficulty 4/580–180 hrs$15000–350001966-1977

This is the standard capable trail build for an early Bronco — not a show truck, not a dedicated rock crawler, but a truck that will handle moderate-to-difficult trails reliably and still drive on the street.

**Starting point:** 1969–1977 Bronco with solid floors and frame. Rust-compromised structure adds $5K–$15K to this budget before the build begins.

**Engine and drivetrain:**

5.0L HO engine swap (if starting from an I6 or tired 302): ~$2,200 total with Edelbrock intake and carb
Shorty headers + 2.5" dual exhaust: ~$650
Pertronix ignition: $90

**Suspension:**

Skyjacker 4" complete kit: ~$1,100 (springs, extended shocks, hardware)
Extended brake lines: $80 (safety-critical, don't skip)

**Axles and gearing:**

ARB Air Lockers front and rear: ~$1,160 for both, plus $340 for the twin compressor and ~$200 for line and mounting
Yukon 4.56 gear sets: ~$680 for both axles; add $700–$900 for professional installation

**Tires and wheels:**

35x12.50R15 BFG KO2: ~$1,200 mounted and balanced (5 tires)
15×8 steel wheels, 4.5" backspacing: ~$500 for 5

**Skid plates and armor:**

Transfer case skid, engine skid: ~$500 fabricated or purchased
Rock sliders (tube frame): ~$400–600 fabricated

**Total range:** $15,000–$35,000 depending on starting condition, DIY vs. professional labor, and shop rate.

**Build order:** engine first (so you're not working around a tired powerplant), then suspension + brake lines + alignment, then axle regear, then lockers. Tires last — confirm clearance before buying.

Why it works

capable on moderate-to-difficult trails
streetable daily (mostly)
ARB lockers are transparent until you need them
strong resale as a "clean driver build"

Trade-offs

starting condition dramatically affects budget
ARB locker installation requires professional axle setup
35s at 4.56 gears with a Dana 20 is marginal — 4.88 preferred for 35s

Tools required

floor jack
jack stands
socket set
torque wrench
welder (for skids/sliders)

Parts

Part	Vendor	Est. price
Skyjacker 4" suspension kit	Skyjacker	~$1100
ARB Air Locker front (Dana 44)	ARB	~$580
ARB Air Locker rear (Dana 44)	ARB	~$580
ARB twin air compressor	ARB	~$340
35x12.50R15 BFG KO2 (set of 5)	BFGoodrich	~$1200
15x8" steel wheels, 4.5" backspacing (set of 5)	Various	~$500
5.0 HO long block + Edelbrock intake + carb	Various	~$2200
Hooker shorty headers + 2.5" dual exhaust	Hooker / Various	~$650
Yukon 4.56 gear sets front and rear	Yukon Gear	~$680
Skid plates (transfer case + engine)	Various	~$500

Sources

{'title': 'Trail Bronco build thread', 'url': 'https://www.fullsizebronco.com/forum/'}

Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.