How to swap a 460 into a 1978/1979 Bronco
I found/did this write-up for roughrider78, this should help you with everything you'd need to accomplish!
Installing a 460 in a Bronco, the Right Way!
The 429/460 big block engines from Ford are some of the most popular performance engines in the world. 460s can be found in everything from Pintos to F-350s and from swamp buggies to top-fuel drag cars. Consequently, it is not surprising that the 429/460 is by far THE most popular engine to swap into the 78-79 Ford Bronco.
Although 429/460 engines were not available from the factory in 78-79 Broncos (or any Bronco, for that matter), you can install a 429/460 in a 78-79 Bronco using all factory parts! There is no need to buy expensive engine swap kits or to custom fabricate parts from scratch (in most cases) if you know which engines to buy and what parts you need to get for the swap. So forget everything you have read in 4x4 magazines and all of the rumors and myths that you may have heard in the past and learn how to install a 460 in a 78-79 Bronco the right way!
The best 429/460 engines to install in the 78-79 Bronco are the 460s that were installed in the 75-82 E-Series (Carbureted) vans and the 73-79 2WD F-Series trucks (the 429 was NEVER installed in a Ford truck or van and the 460 was NOT available in 4WD trucks until the mid-1980s). If you can find one of these engines as a starting point for your project, then you will have 90% of the parts you need to install a 429/460 in your Bronco! Nearly everything on these engines, including the accessory brackets, oil pans, exhaust manifolds, carburetor linkage, and the automatic transmission kick-down cables will bolt in to your Bronco.
The E-Series vans are the best of the two to look for for several reasons. There were many more E-Series vans built with 460 engines than there were F-series pickup trucks. The Econoline vans also had closer-fitting exhaust manifolds and some of them used the Saginaw (GM Type) power steering pump. The close fitting manifolds will give you a little more room to work with in a tight engine compartment and the Saginaw power steering pump is a little better unit than the stock Bronco Ford pumps. Just make sure you get everything you can with the engine, including the PS pump, hoses, and all of the accessories including the alternator, A/C compressor, and pulleys. It's better to be safe than sorry!
Another alternative to the Pickups and Vans is to buy a 429 or a 460 out of a 1968 to 1978 full-size Ford, Lincoln, or Mercury passenger car. While these engines will require you to locate a few more parts than the Van & Truck engines, they are far more plentiful and are often in better shape. Below is a chart that shows common full-size Ford automobiles and the years the 429/460 engines were available.
Motor Mounts -- The most common motor mounts to use for the this swap are the L&L 429/460 Bronco mounts. These mounts retail for around $100.00, require no modifications or relocation of the engine or transmission, and have a lifetime warranty.
Oil Pans -- Unless you have a 2" or higher suspension lift on your Bronco, you will probably need to use a rear sump oil pan in order to fit a 429/460 in your Bronco. Some people have been able to use the front-sump pan on stock-height Broncos, but the general consensus is that the rear-sump pans are not only a better fit, but will be needed to keep the oil in the pan when driving up steep hills, so try to avoid front-sump pans if possible. Front-sump pans work fine in a passenger cars but are not adequate to keep the oil where it's supposed to be in a 4x4. The E-Series vans, F-Series pickup, and some Lincolns already have rear-sump oil pans, but some Lincolns and some of the Ford and Mercury cars used front-sump pans. If your engine has a front-sump pan, then you can either try to find a rear-sump pan in a salvage yard or you can buy one from L&L products. L&L's pan retails for around $200.00.
Exhaust Manifolds -- Again, if you have a E-Series van or a F-Series pickup 460 engine, then your manifolds will fit in the 78-79 Bronco. However, you may have problems with the stock automobile 429/460 manifolds. Some of them will work, some of them wont. If the pair you have will not fit, then you can either buy a pair of used truck & van manifolds from a salvage yard or purchase new 78-79 Bronco 429/460 Bronco exhaust headers from Hooker Headers and L&L products. The Hooker headers retail for around $120.00 and the L&L headers, depending on the type of header (inside or outside of fender), the type of plating, and where you purchase them from can retail for up to $450.00.
Power Accessories & Brackets -- Getting the Power accessories and brackets properly installed can be one of the trickiest parts of an engine swap. Fortunately, most Ford products from the '70s used a standard set of accessories. Most Alternators, A/C compressors and PS pumps will interchange. In the case of the 78-79 Bronco, all of its accessories will bolt up to the F-Series 460 engines, and all but the PS pump will bolt up to the E-Series 460 engines that came with the Saginaw pump (just re-use the van's PS pump). One word of caution when using the Saginaw pump on a Bronco: you might have to use a custom-built hose or at least a stock hose that has been modified to make it work properly with the Bronco's steering box.
Regardless of what type of 429/460 you buy, make sure you get all of the accessories and brackets with it. Chances are most of it will fit. The only accessory that may give you problems is the A/C compressor. There were basically 5 types of A/C compressors installed on 429/460 engine from 1971-1986. Listed below is a chart showing each type of compressor Ford used and which year and model vehicle it was installed on. The darker-shaded areas show 460-powered Fords with A/C brackets that should allow you to bolt your Bronco's factory or dealer-installed A/C compressor to your 460 engine.
Cables, Hoses, and Linkage
Now it's time to round up the remaining "little" things that most people take for granted. This section covers the installation of the throttle cable, radiator hoses, and automatic trans kick-down linkage.
Cables -- Most 78-79 Broncos used a cable style throttle linkage. This type of linkage is very flexible and lends it's self to a variety of Ford engines. Most 460 4V engines also had the cable type throttle linkage. Your Bronco's throttle cable should bolt up to these engines with only very slight adjustments. Some 78-79 Broncos used a rod-type throttle linkage, and if your Bronco uses this setup, then you will have to either make a custom linkage rod or convert your Bronco over to the cable-type setup.
Hoses -- There are several types of hoses you can try when installing a 460. You can try the upper & lower hose from a 78-79 F-Series 2WD with a factory 460 as a place to start. Some people have been able to use the factory 351M/400 lower radiator hose and the stock upper hose with a little trimming on their 460 swaps. One person was even able to get the upper radiator hose from a 87-92 F-150 with the 302/5.0 engine to work! Another person says that the lower hose from a '75 F-250 2WD with a 460 will work perfectly after cutting about 3" off of the radiator side of the hose. It' just going to take some trial & error to find a set of hoses that will work on your radiator with the particular engine you are putting in. The safest bet is to measure the length from the radiator to the water neck & water pump and buy a set of universal flex hoses of the proper length and inside diameter. The next time you replace the hoses they should have taken a permanent set and you can match them up to a pair of pre-molded hoses at you local auto parts store.
Linkage -- If your Bronco has an automatic transmission, then make sure you buy the kick-down lever along with your 460 engine (if it had an automatic). If the lever doesn't fit or your 460 engine did not come with one, then simply use a kick-down lever from a 73-79 F-Series pickup with a 460 and automatic transmission.
So far I've talked about how to install a 429/460 and get everything hooked-up and running. However, there are just a few other minor factors that you should be aware of when installing one of these power houses in your Bronco.
Transmissions -- As far as the tranny goes, the 429/460 will bolt right up to your Bronco's stock transmission bell housing, however, there are a couple of things that may give you some problems you need to be aware of. First, some of the 429/460s used a different input shaft than the one that the Bronco 351M/400 uses. In this case, you are going to have find the correct torque converter/shaft combination that will work or have a custom shaft made for your swap. Second, the the 429/460 used two different types of flywheels -- one for the automatic transmissions and one for the manual transmissions. You need to make ABSOLUTELY sure that you are using the correct flywheel with your Bronco's engine and transmission! One other word of caution -- DO NOT try to reuse your 351M/400 flywheel with a 429/460 engine. Do what ever you like with it (make it into a clock, throw it at someone you don't like, or whatever) just don't reuse it! The 351M/400 flywheel will bolt right up to the 460, but all 429/460 engines are balanced differently than the "M" engines so the "M" flywheel simply will not work. Also keep in mind that the '79 and up 460 engines are balanced differently than the 78 and older 460s so be ABSOLUTELY sure to buy the correct year flywheel for your engine.
Coil Springs -- The 429/460 weighs about 145 lbs more than the stock Bronco 351M/400 engines. If your front coil springs have some age on them then your Bronco may sit a little lower in the front once your 429/460 is installed. If this is a problem, then you may want to consider purchasing new front coil springs. If your Bronco sits extremely uneven, then you might want to install a new set of "leveling" coils from companies such as JC Whitney and James Duff.
Cooling -- The 429/460 puts out quite a bit more hose power than bone-stock 351M/400 engines, and more horsepower means more heat! The stock Bronco radiators are NOT adequate for a supped-up 351M/400 engine or any 429/460 engine. Consider upgrading your radiator to a HD 3-core or 4-core radiator to keep your new engine running nice and cool.
Starters & Distributors -- Before you drag your old 351M/400 engine to the beach house and install your new anchor on your boat, pull off the factory distributor and the factory starter. Why? Because they will bolt on and work perfectly on your new 429/460 engine. If your 429/460 has a points-type distributor (most pre-1975 engines) then you should reuse your Bronco's Duraspark II electronic distributor. It will really bring that old 429 or 460 to life! Also, your new engine may have a bad starter on it or may have not come with one at all. You might as well save your self a few bucks and use the Bronco's original starter.
One other neat little item you can use on your 429/460 is a 92-93 7.5L F-Series gear-reduction starter. They are smaller, weigh less, and have more torque than the standard full-size Ford 351M/400/429/460 starters. If you plan to install headers on your Bronco with a 429/460 engine, then the gear-reduction starter will give you a little more room to work with in a cramped engine compartment. You can purchase these starters from most auto parts stores for around $200.00.
This article is mostly a combination of tips & tricks from others who have installed 460 engines in their Broncos. Keep in mind that this swap is not an exact science and some of the ideas listed here may not work with your particular engine and your particular Bronco. Not all 460 engines are the same, not all radiators are the same, and not all Broncos are the same either. Any time a swap like this is attempted you are going to run into some unforeseen problems. It may take some "Junk Yard Hopping" and plenty of trial & error to get all the parts you need but what's the point of having a hobby if it wasn't a challenge? If all of this seems like too much trouble and you have around $1,000.00 just burning a hole in your pocket, you can always buy the complete 429/460 swap kit from L&L products. Another item to keep a look out for is a 78-79 Bronco or F-Series 4x4 that already has a 429/460 installed in it! You never know because the Bronco/429/460 is so popular that you just might luck out and find one.