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Ford Bronco
1978–79

Factory gearing, tires, angles and brakes for the Bronco, and what the usual upgrades do to it. Every number is from the maker's own figures unless the calculators say otherwise. A few figures here are still waiting on a factory document; the calculators mark them.

Use this truck in the calculators
104 in wheelbase · 32.8 in front · 43.5 in rear overhang
in
Axle ratio3.5Factory
Crawl ratio46.8:1Best trim: Optional 7.00-15D tube-type (7.00x15D TT tires)
Angles37.5 · 24.9 · 23.4°Approach, breakover, departure
Clearance7.8 inFactory figure
Highway mpg8Estimate, not EPA rated

Trims

3 we have figures for
TrimTireTransmissionAxleAnglesClearanceOpen
Std L78-15B, 351M/400, 4-speed part-time29.04-speed manual, 4-speed manual3.537.5 · 24.9 · 23.47.8 inUse →
Std L78-15B, C6 automatic (part-time or full-time 4WD)29.03-speed automatic3.537.5 · 24.9 · 23.47.8 inUse →
Optional 7.00-15D tube-type (7.00x15D TT tires)28.34-speed manual, 4-speed manual, 3-speed automatic3.537.5 · 24.9 · 23.47.8 inUse →

Size

Wheelbase
104 in
Front overhang
32.8 in
Rear overhang
43.5 in
Height
74 in
Body
SUV
Stock tires
28.3, 29.0

Transmissions and low range

4-speed manual (New Process 435, granny 1st)
6.69 · 3.34 · 1.79 · 1
4-speed manual (Borg-Warner T-18, reported)
6.32 · 3.09 · 1.69 · 1
3-speed automatic (C6 Cruise-O-Matic)
2.46 · 1.46 · 1
Low range, np205
1.96:1
Low range, np203
2:1

Axles

Front
Dana 44 solid axle, coil springs/radius arms (3550 lb)
Rear
Ford 9 in (3750 lb)
3.5 ratio
All trims
Ratios made for it
3.54 · 3.73 · 4.1 · 4.56 · 4.88 · 5.13

Brakes

Front rotor
11.72 in, 298 mm
Front caliper piston
73.0 mm
Rear drum
11.03 in, 280 mm
Rear
drum

Suspension

Front
radius arms with track bar, coil springs (Dana 44)
Rear
leaf springs, solid axle
Rear layout
Leaf springs

Fuel economy

Highway, not EPA rated
about 8 mpg
Where it comes from
Owner average, 9 trucks, mixed driving (1979 Bronco 351M/400 V8, C6 or 4-speed)

Aftermarket bumpers

2 listed

Makers almost never publish angles, bottom heights or how far a bumper tucks, so these fill in as owners measure them. Measured yours? Add it on the rig page and every owner of this Bronco sees how it does on their tires and lift.

Front 2

Rear

None listed yet.

Every calculator, set up for the Bronco

Tire sizeBigger tires: speedo, clearance, angles and brakes.Compare tiresRegearHighway RPM on every ratio and mpg.Pick your gearsCrawl ratioHow slow it creeps, against other trucks.Work out crawlSpeedometerWhat it really reads on new tires.Fix your speedoLinksAnti-squat and what a lift does to it.Check your linksYour rigBuild sheet and measured angles.Start a build sheetLeaderboardsWhere the Bronco ranks against every stock truck.See where it ranks

Source: broncograveyard.com. Front Dana 44 and rear Ford 9 in use different ratio steps (front 3.54 vs rear 3.50 style pairing from the factory), so buy a matched front/rear set.

Use at your own risk. These calculators are here to help you plan and to inform your decisions, not to sign off on a build. Many numbers are estimates worked out from factory figures, and some factory figures are not yet confirmed. Check every number against your own truck, its manuals and a qualified shop before you buy parts, cut, weld, lift, regear or drive on it. Long Range Desert Tools is not liable for anything you do based on these calculators or their results. The full terms are in our policies.