Which brings up injectors-are they properly sized for the crate motor you're installing? You need new engine mounts unless you already have aftermarket mounts. We recommend urethane mounts as they hardly affect vibration but are vastly more durable than rubber. Don't forget to change the transmission mount, too.
Moving beyond the engine compartment, consider the clutch, transmission, and driveshaft, dealing with each as necessary. Unless you just installed a new clutch, plan on a new one with the new engine. Transmissions are typically OK and most Mustang transmissions are easy enough to change on their own, so they need not be changed automatically along with the engine.
Driveshafts are forever, but U-joints aren't. Replace them as necessary is the fiscally responsible advice; we swapped in an FRPP aluminum driveshaft to easily gain new U-joints and lose a few pounds.
And what about the rest of the car? Are the tires good? Do you need a brake upgrade to match your new power? The cost must be factored into the budget and the parts acquired before grabbing the wrenches.
One of the best deals going...
One of the best deals going is FRPP's M-6052-B silicone hose kit. Durable as sin, these seemingly indestructible hoses will outlast any engine and are an excellent upgrade. Developed for police-pursuit Foxes, these molded hoses offer a perfect OEM fit. Well ... Ricardo finds trimming a quarter-inch off the small 90-degree thermostat bypass hose makes it easier to install.
Everyone has their own clean...
Everyone has their own clean quotient, but don't forget that when the engine is out there's no better time to clean from the firewall forward. It's possible to spend days on this-we dedicated over 15 hours on the job-so plan generous downtime in your schedule if you're looking to impress. We found Simple Green Max Degreaser from a gallon jug, diluted 50-50 with water and put in squirt bottles, was amazingly effective yet didn't hurt the paint.
Our X302 came on a wooden...
Our X302 came on a wooden pallet closed with cardboard. Stripping back the cardboard left the engine nicely exposed, supported, and easy to dress. Because the oil pan rails hold the engine, almost everything could be bolted to the engine, including the engine mounts, flywheel, clutch, headers, and so on. With a Mustang-friendly double-sump pan, the X302 is ready-to-go in that respect. However, it comes with an SN-95 dipstick; we substituted our existing Fox dipstick, which works fine.
Making the Swap
We don't have the room here to detail an engine change step-by-step, but in general, it's best to unhook the original engine enough to lift it out of the car, then strip it as necessary while it's out on the ground. At the same time, the new crate engine can be dressed with as much as you can get away with-headers are a joy to install out of the car-then put into the car.
Remove the vulnerable radiator before the engine, and you'll find pulling the transmission makes handling the engine that much easier. You might want to support the rear of the engine with a floor jack or stand once the transmission is out, especially if the engine mounts are shot.
Obviously you need some large tools, such as an engine hoist. A transmission jack and muffler stand (if you're lucky enough to work on a hoist) are nice, but not absolutely necessary. A suitable concrete floor is a must, and it's best to plan on having the car down for a week, typically because last-minute parts are required. A helper or two are mandatory in spots as well. For these reasons, most folks opt for pro installation, but if you have the tools, go for it.
Air conditioning turned out to be the least of our installation worries. By unbolting the compressor from the engine and laying it over a fender, it was possible to swap engines without breaking into the air conditioning system. That means no trip to an AC shop to have the system discharged and refilled later. You have to work around the bulky AC hoses and compressor, but it's still the best option.
Another small, easily over-looked...
Another small, easily over-looked part is the oil-pressure sending unit. We washed our old one and threaded it into the new engine. The chrome fuel-pump block-off plate is stock on the X302; a fuel-pump eccentric is too, so carbureted applications require simply bolting on the engine-driven fuel pump. The FRPP oil filter is included with the engine; a water pump is not. We ordered FRPP's M-8501-C50 reverse-rotation aluminum pump, which fits all '86-'93 Mustangs.
Ford Racing fits its top-of-the-line...
Ford Racing fits its top-of-the-line polished valve covers to the X302, and they look great. We wanted to stay with a black theme in our black Fox, however, so we ordered a black Edelbrock intake manifold. While dressing the engine at GTR, we lucked out when another customer wanted to trade their black valve covers for our polished set, giving us an all-black top end. It was another way choosing our local shop paid off.
Ricardo told us not to but...
Ricardo told us not to but we insisted on fitting a new power steering pump, just to reset the clock on what was rapidly becoming a "new" 5.0. That meant pulling the taper fit pulley off the old PS pump, which Ricardo is getting ready to do here. We should have listened, as the new pump is way louder than the old one we removed! "Typical!" said Ricardo. Stick with your existing pump if it's quiet and doesn't leak. Rebuilding your stock pump is a good option as well.
Because we wanted functioning EGR, we wanted to use the stock threaded fittings at rear of each head. These came blocked with steel fittings on the X302, and sealed with red Loctite. They wouldn't unscrew, so Ricardo drilled them to form an air passage. Greasing the drill bit and fishing for leftover chips with a magnet got the job done. As there is no gasket at this head-to-EGR-pipe connection, Ricardo used copper ultra-high-temp RTV silicone as a gasket.
If you have stock rubber heater hoses sticking out of the firewall, carefully remove them. Slitting them lengthwise first is smart as the heater-core nipples have a tendency to rot and pull out now that Fox heater cores are 20 years old. This begs the smart decision to replace the heater core-a hateful under-dash job you just might have to put off for a few more paychecks. If so, and your Fox already has silicone hoses, just leave 'em. The hoses might be slightly stained, but they can be safely reused, thus avoiding a wrestling match with a weakened heater core.
Finally, consider what to do with your old engine. Most people are happy enough to donate the old hulk to the install shop. Also, a used T-5 transmission that isn't beat to death is trade-worthy, so you might inquire if your core parts have any value to the shop.
With the GT-40X cylinder head's...
With the GT-40X cylinder head's larger-than-stock exhaust ports, the stock crimped-tube manifolds are choked. This restriction makes using a proper 15/8-inch, mandrel-bent, short-tube header a must. FRPP has just the part in these M-9430-P50 stainless steel short-tubes, which fit great and are built to last. As a bonus, there's never an easier header installation than when the engine is out of the car. As a caution, we didn't like the fit of the supplied gaskets (bolt hole misalignment) and stock gaskets have under-sized port openings, so we used Fel-Pro 1415 gaskets, which fit in all dimensions, were thicker, and obviously of high Fel-Pro quality.
After nearly 200,000 miles,...
After nearly 200,000 miles, another system we wanted to reset was the ignition. With stock 5.0 distributors rarely needing replacement, we opted for a new harness, cap, and rotor. The wires are especially nice as they are fully built, numbered, and the correct length. Even so, we ended up with a high-rpm miss, so a new coil may be in our future as well...
Also on our hit list was a...
Also on our hit list was a fresh starter. Ford Racing carries the latest Ford corporate mini-starter, PN M-11000-A50. It packs plenty of cranking torque, weighs less than our stock starter, and has OEM reliability. Its modern sound and high-rpm cranking still surprise us every time we hit the key. Installation requires bypassing the fender-mounted starter solenoid, but that's no more than moving a wire from one post to another.