Sorry for the length, It's lunch break and you got me going ....
I'm not sure the answer to suspension / brakes etc. are as easy as you might think. As an example - Brakes:
Depending upon the wheel size you plan on using you will have the choice of 11,12,13 and even larger rotors, of different styles. Then there are calipers with 1, 2, 3, 4, and 6 pistons (4 and 6 piston calipers are really intended for race use). Then there is the master cylinder and any boost module - Want more cylinder pressure and brake engage speed, go to a smaller master cylinder (increased hydraulic pressure)
Also I would budget the costs at about 40% Engine, and the other components at 60% (my guess)
Just talking engine now...
The first thing you MUST decide:
1) How street legal do I need to be (emissions)?
2) How reliable do I expect my engine to be?
As a general rule (not always) the more power you develop the less reliability.
This is mostly true when you change the basic design of the engine by boring and stroking the engine, which involves enlarging the cylinder bore, new cylinders, and changing the stroke distance with a new modified crank. There are a number of good quality kits out there to do this, but the bottom line is that you are pushing the original design of the engine. You can purchase a bored and stroked engine at pretty reasonable cost, but remember - They don't come with a warranty for a reason.
What's available - what should you do???
This forum is good, but also talk to as many people as you can about your plans. Go to a good speed shop in your area and talk with some of them.
HP without bore and stroke (you would need these things on a stroked engine as well)
Exhaust - a basic requirement for every engine to make added HP.
For the 5.0 -
Exhaust: 1 5/8" to 1 ¾ header tubes into a 2 ½ or 2 1/4" primary.
For dual exhaust use a free flow 2 1/2" CAT and good 2 1/2" mufflers and pipes. (I prefer Flowmaster, this is your basic stang setup)
For single exhaust run the primaries into a 3” collector into 3” Cat, muffler and pipes.
Intake -
There are many available - Ford GT and aftermarket. The stock Explorer intake is the cast aluminum GT model. These are good flowing intakes and can be extrude honed for about $600, or you can buy an aftermarket intake. A basic principal is that the shorter the runner the more top end HP, the longer the runners the more Low end. Trucks use something like 17" tubes, street performance intakes come in at about 15", high performance / track intakes are 12" or shorter.
Edelbrock, and Holly have developed "systems" with heads, intake, & cam that are quite good. TrickFlow also has systems, but my opinion is that they are designed more for track use (especially their cams) than street use, but they are GREAT products. If I were going Trickflow I would investigate their compatibility with a high torque cam from another vendor, but that’s just for my application – off road / torque over HP.
Heads
A good set of heads is essential... but what’s good?
There are trade offs here; Aluminum heads are not always the answer, Iron heads can actually make more HP. Iron is heavy; Aluminum is lightweight. Iron holds a steady heat, Aluminum looses heat too fast and you loose power just keeping the heads hot. Iron contracts and expands at rates that are the same as the block; Aluminum does not and requires more expensive head gaskets.
The big deal about Aluminum heads is that that's what the aftermarket uses to build heads that FLOW well, and reduce weight. Flow is what you are after. Iron heads properly ported will also Flow well and make great HP. (I ported my set of GT heads instead of going to Aluminum to save a few bucks, >$400). The explorer P heads already flow quite well. A mild porting job would make them competitive with many aftermarket aluminum heads.
CAM:
This is often called your engines heart beat or "pacemaker". Selecting the right cam will make or break your project. Choose carefully. This means study and learn about cams. It will control the RPM range where you make that HP. There is too much to discuss than I can include here.
Injectors:
Changing injectors may be necessary. You might need to go to 24# injectors. But you should be careful - We do the majority of our driving at lower rpms where we don't "exercise" the injectors. 24# injector spray pattern will be compromised atthose lower RPM ranges. On the other hand at the higher rpm ranges the 24# injectors are necessary when making over about 350 HP. 19# injectors are good up to about 400 HP. It sounds like you will put this engine to the test, so you will most likely want 24# injectors, but they could be an upgrade item.
Fuel pump:
Go ahead and get a 190 lph or 250 lph pump now. You will need it, and you really only want to change this item one time. Get a used one - 190 lph pumps can be had used for $50 - $60.
Fuel Rails:
The stock should work for starters; this will be future upgrade item. You will only notice their impact at the high end.
Fuel regulator:
Go ahead and get an adjustable one now. With the other mods you will probably need it.
Throttle body & MAF:
To make the HP and get ready for a supercharger go with a large TB and MAF now. Use whatever the supercharger would recommend. AccuFab & BBK are good sources for the TB. Match the MAF as well. I prefer C&L (
www.cnlperformance.com), they make a good product and give good help (I have heard lots of quality control problems with the ProM / Pro-Flow MAF. It is better metering on paper, but they have lots of problems with delivered product).
Engine Control Unit (EEC)
You have a 97 so you have EEC V system. I am not familiar with EEC V performance parts / replacements. A replacement chip will probably be required, but you will need to get it re-programmed with every major change you make if you do the project in steps. The other alternative is to use the stock chip until you finish the mods and get one once. The high-end alternative is the EPEC programming system - program your own. It should work with the 97 EEC V, but you would need to check it out. There may be some other programmable EEC V systems out there that I don’t know about. There are some for the EEC IV.
With the aftermarket products I'm sure you can make 300 to 370 HP without stroking. Put on a supercharger and you’re in the 450+ HP range. I would expect to spend $3K to $4K on parts, and another $3500 for a supercharger. You would also have to buy these components for a stroked engine. (A good stroker short block should cost something like $3K and up, and there is no mileage warranty)
Some WEB sites:
www.edelbrock.com
www.holley.com
www.trickflow.com
www.compcams.com
www.crower.com
www.cnlperformance.com
www.pro-flow.com
For new and used parts for 5.0 liter at good prices:
www.corral.net