Here is some good vacuum routing information.
Buying yourself an Early Bronco is about the best thing that you can do. It will give you years of enjoyment, an excellent opportunity to learn, and a means to meet quality people and forge lasting friendships with Early Bronco lovers all over the world. This article is intended to address some of the common things to look for when buying an Early Bronco so that you will have some knowledge as to exactly what you are getting into.
The History: (from Bronco.com / Bronco Driver.com)
The Ford Bronco was introduced to the public in August of 1965 to compete against Jeep’s CJ-5 and International Harvester’s Scout in the burgeoning recreational four wheel drive vehicle market. The first Broncos were very spartan without options such as power steering and an automatic transmission. The first models were available only with a 105 hp 170 cid six cylinder derived from Ford’s Falcon lineup. The only available transmission was Ford’s 3.03 three speed manual with a column mounted shifter. Transmission ratios behind the six cylinder were: 3.41:1 first, 1.86:1 second, and 1:1 third. When the 289 V8 option was introduced in March 1966, the three speed manual behind it had ratios of: 2.99:1 first, 1.46 second, and 1:1 third. The transfer case was a Bronco specific Dana 20 with a low range ratio of 2.46:1. Unique to the models was a tall shifter with a shift pattern matching that of the T-handle shifter, but with a J- handle style ball mounted on top. Most ’66s also had rear shock absorbers that angled forward in front of the axle with stud mounts at the top instead of the later rear-canted eye mount shocks. The Bronco, with a 92 inch wheelbase was offered in wagon, half cab, and roadster configurations. The roadster option was not very popular and was discontinued after 1968. Standard brakes were 11 x 2″ front drums and 10 x 2.5″ drums on the rear on the small bearing (2780 lb.) axle and 11 x 1.75″ drums on the large bearing(3300 lb.) axle. All Broncos employed a Ford 9″ rear axle and until 1971, a Dana 30 front axle rated at 2,500 lb. Axle ratios were 3.50:1, 4.11:1 and 4.57:1(6 cyl. only). The standard gas tank held 14.5 gallon with an optional 11.5 gallon second tank available. Options for ’66(including dealer installed accessories) included: Warn free wheeling hubs, snow plow kits, winches, tachometers, Air Lift front auxiliary springs, trailer hitches, tow hooks, etc. Most of the options and many others were included through the Bronco’s twelve year run. Production for the 1966 year totaled 18,200 units.
The Sport Package was introduced in 1967. This package included bright finished horn ring, windshield drip, head and tail lamp bezels, side window frames, instrument panel trim and tailgate handle, cigar lighter, chrome-plated grille, bumpers and front guards, red die cast F-O-R-D letters appliquéd to the grille, and 15″ wheel covers. A bright trimmed hardboard headlining and vinyl floor mat were also added to the Sport Wagon. A dual master cylinder with a split hydraulic system and self-adjusting brakes was also new. Back-up lights were now standard and an 11.5 gallon auxiliary fuel tank option was available. 16,100 Broncos were built in 1967.
Bumpers with curved ends and side marker reflectors immediately distinguished the 1968 models from their predecessors. Locking front hubs, new inside door handles and “soft” window crank knobs were other new options. This was also the last year for the 289 V8 and the roadster option. 1968 production was 15,700 trucks.
1969 was a big year for the Bronco with production jumping to 19,200 units. The 302 V8 replaced the 289 V8. Two speed electric windshield wipers replaced the vacuum units several months into the production run. Amber lenses parking lights replaced the previously used white lens. The Sport models now had aluminum door panel trim, pleated parchment interior, and a rear floor mat when the rear seat was ordered. Some sources say the removable top feature was discontinued, although we enthusiasts know better! The steering stabilizer became a standard feature along with improvements in NVH.
Repositioned side marker lights and reflectors were the most obvious change to the 1970 Broncos. The Sport Bronco became a model rather than an option package. 1970 also saw the first application of evaporative emissions recovery systems with gas tanks on models so equipped losing capacity to 12.7 gallons and 10.3 gallons in the main and auxiliary tanks respectively. 18,500 Broncos were built in 1970.
The stout Dana 44 became the standard Bronco front axle early in the 1971 production year, replacing the weaker Dana 30. New options included a remote control left hand outside mirror, a new headliner for the pickup, and a heavy duty radiator. The special edition Baja Bronco by Bill Stroppe and Associates was also introduced this year. Stroppe took a Bronco wagon and added a roll bar, dual shocks front and rear, Gates Commando tires, fender flares, larger tires, rubberized steering wheel, bumper braces, power steering, automatic transmission, special nameplate, and red, white, blue, and black special order paint. A total of approximately 650 Baja Broncos were produced between 1971-1974. 18,700 Broncos rolled off the assembly line in 1971.
1972 was the last full year for the T-handle transfer case shifter and the ‘302’ emblem disappeared from the front fenders of V8 Broncos. This was also the last year for the beloved half cab. The Ranger trim package was introduced at mid-year and consisted of new stripes, argent grille, color-keyed pile front and rear carpet, deluxe wheel covers, wood-grained door trim panels, ‘Ranger’ tire cover, cloth-inserted bucket seats and a fiberboard headliner. Gas tank size continued to shrink with the auxiliary tank now holding 7.5 gallons. 1972 Bronco production totaled 18,300.
When the Bronco was introduced in the mid-sixties, its main competition was the Scout 800 and the Jeep CJ-5, both spartan vehicles to say the least. By the early seventies, with the introduction of the Chevrolet Blazer and the Scout II, it became painfully obvious that the Bronco was beginning to fall behind the competition. In 1973, Ford finally answered the calls for modernization by introducing the C-4 automatic transmission option and optional power steering. The C-4 had ratios of 2.46:1 low, 1.46 second, and 1:1 third. The power steering box was a Saginaw unit with 5.3 turns lock-to-lock. The base engine was bumped from 170 to 200 cubic inches. The J-handle transfer case shifter was introduced shortly after the model year began and the low range transfer case ratio became 2.34:1. These changes helped push early Bronco sales to their second best year ever: 26,300.
By 1974, the 200 c.i.d. six cylinder and 4.11 axles were no longer available in California. A new emissions package was also introduced for California Broncos. Some subtle changes were made mid-year to the J-handle shifter mechanism in response to complaints of tough shifting. The transmission selector was lighted starting in ’74. 21,400 Broncos rolled off the assembly line in 1974.
Unleaded fuel engines and catalytic converters were the new items added to the Bronco in 1975 in the face of increasingly strict emissions requirements. Some sources also say that the cam timing on ’75 engines was retarded to help with emissions as well. Sport and Ranger models received the F-Series steering wheel for the year. GVWs and ride heights were revised. Among the new options was an 800 watt engine block heater for folks in cold climates. Bronco production shrunk to its lowest ever in 1975 with just 13,200 trucks produced.
The bicentennial year brought several key improvements to Ford’s sport utility, most notably the addition of long overdue power assisted front disc brakes. The rear brakes were upgraded to 11 x 2.25″ drums. The steering box ratio was shortened to 3.8 turns lock-to-lock. The dreaded Y steering linkage was also introduced in 1976 along with a front anti-sway bar. A Special Decor Group comprised of a flat black-finished grille, tape stripe, bright windshield molding, and side window frames and wheel covers was introduced mid-year. 14,500 Broncos rolled off the line in 1976.
Everyone knew the early Bronco’s days were numbered in the face of stiff competition from the Blazer and Chrysler Corporation’s Ramcharger and Trail Duster trucks. The 1977 Bronco in many ways represented the best of the breed. There were very few changes from the previous year; the most important one for enthusiasts being the introduction of the heavy duty 9″ rear end housing. The most obvious exterior change was the introduction of gas tank doors replacing the previous exterior mounted caps, in line with the introduction of doors on the F-Series and Econoline vans. The rear marker lights were mounted vertically to give clearance for the doors. Some previously standard items, such as a passenger’s side seat and padded instrument panel, were made optional this year. Unique to the ’77s is a 14.4 plastic gas tank and an 8 gallon auxiliary tank. In its final year of production, 30,700 Broncos rolled off the assembly line before the large Bronco took over in 1978.
The early Bronco today enjoys a cult-like status among four wheel drive and collector car enthusiasts alike. Its simple, sturdy construction, V8 power, and excellent maneuverability ensure good off road performance and provide a platform on which many modifications can easily be made. The popularity of the classic 1966-1977 Ford Bronco will no doubt continue to soar in the years to come.
There were four trim packages for the Bronco. There was the base Bronco, Bronco Explorer, Bronco Sport, and Bronco Ranger.
One of the major factors when buying an Early Bronco is deciding what you are going to do with it. If you want a project to restore to original condition, then any year would be a good choice. If you are planning on making it into an sturdy off-road vehicle, then there are several other factors to consider. Ford phased in the Dana 44 from axle in the middle of the 1971 model year. The Dana 44 is considerably stronger than the Dana 30 that used to come standard. Other options that make off-roading easier is power steering (1973) and disc brakes (1976). There were two different styles of Dana 20 transfer cases available in the Bronco, identified by their shifter patter. From 1966 to 1972, the Bronco came with the t-shifter style transfer case which had a more robust shifting mechanism and lower low range (2.46:1). From 1973 – 1977, Ford used the j-shifter style transfer case with a 2.34:1 low range ratio.
Since Broncos are a minimum of 23 years old and made from metal, chances are that they are going to have some rust. The main problem spots on the body of a Bronco are the rocker panels, door posts, floor pans, inner fenders just in front of the firewall, windshield frame, hard top gutters, and tailgate. The nice thing about owning a Bronco is that all of these pieces are available for replacement, but that will require ability, time, and money on the part of the buyer.
The later model Broncos came with additions like power steering, power disc brakes, and an automatic transmission and tend to fetch a higher price. The trim packages like the Sport and Ranger version also have a lot of chrome which, if in good shape, is quite valuable. Sometime in the late ’60s models, electric wipers replaced the vacuum-controlled wipers.
Upgrades are the best part about buying a Bronco for hard-core off-road use. There are many upgrade options. Regardless of what you buy, you can determine what type of transmission you would like. Bronco enthusiasts will always debate whether an automatic or manual transmission is better off-road, but it really comes down to personal preference and use. The most common upgrade for a manual transmission is the NP435, which is readily available from heavy-duty Ford trucks. The auto crowd has the option of the Ford C6, AOD, and AODE transmissions. Engine upgrades are also quite popular. Many people choose to swap in a 1989-1993 Ford HO 5.0 engine to take advantage of the benefits of fuel injection. Others stick with carburetors and build some incredible 302 and 351 engines. Suspension modifications are also widely varied. There are a lot of aftermarket kits available to lift and maximize the amount of articulation that you can get under the Bronco. You can also swap in four wheel discs, power brakes, power steering, larger axles, larger engine, etc.
Ordinarily you wouldn’t consider other owners when buying a car, but Bronco owners seem to be a rare bunch. There is a large, nearly fanatical following for the Bronco. Clubs all over the country get together and take their rigs to the limits. You can join the Early Bronco Mailing List (EBML) bronco.com, classicbroncos.com or broncofix.com and instantly be in touch with over 1000 other Bronco owners around the country. It isn’t rare to hear stories of people letting other Bronco owners use their houses, garages, spare parts, and skills to help them out. It’s an elite club and the owners are very high quality people.
There are many Early Bronco websites available on the internet, and that is a great place to see what can be done to the Early Bronco. Just on this site, there is a wide array of possibilities displayed. The sites are also a valuable source of information on how-to for most projects you decide to undertake.