Read and learn Matt
The 96-98 DOHC motor is an all aluminum engine. The block is made by a company called Teksid. This is an Italian company that also makes blocks for Ferrari. The block has been used in many high powered applications, including John Mihovets (sp?) 6 sec. Cougar. The block and forged crank can withstand serious power stock, the myth saying around 1000 hp. The DOHC also features six bolt mains.
The rods and pistons are powdered metal with cracked rod caps. These are the weak links in the engine. Though they are fine in an N/A application they were never designed for FI.
The heads feature two intake valves and two exhaust valves. Each intake valve has it's own runner/port while the exhaust valves use one common port. The dual intake runners are quite large and not the best for an N/A application. To help boost low end power production there is an Intake Manifold Runner Control (IMRC's, you will hear alot about these when discussing the 96-98 Cobras) inbetween the intake manifold and the heads. The IMRC has a butterfly that blocks one of the ports/intake valves at each cylinder. At 3250 rpms a controller under the intake opens these butterflies to allow full airflow to all 4 intake valves. This is what gives the 4 valve it's top end pull and noticeable increase in power.
The DOHC engines also feature an oil cooler, high volume oil pump and a windage tray. These all help to keep the engine well lubricated since the heads need a ton of oil to lubricate the valvetrain. Though it's only recommended to run 6 quarts alot of people run 6.5 or 7 to help keep the pump submersed while driving aggresively. The pan has plenty of room to run the additional oil without the crank swimming in it. Unlike the 5.0's where it was common to drop a quart in order to gain some power, the 4 valve requires every bit of 6 quarts due to the amount the heads hold.
I think that's about all. If anybody ever wants to learn more about these great engines you can visit any of the forums or pick up a copy of Sean Hylands book on building 4 valves. There is some great info in there.