1994 Mustang GT & 1996-2001 Mustang Cobra - Late-Model Corral
Miles Cook Answers Your '79-'04 Tech Questions
Nitrous 5.0I'm a newbie in the Mustang hobby, but I think I'm starting out with a good basic car to learn more about the seemingly endless stream of available information. My '91 LX 5.0 with an AOD is totally stock except for a DynoMax exhaust system and a 65mm throttle body. The problem is, I have several friends with 5.0s and their cars have T5 five-speeds. Of course, their cars are quicker than mine, and I'd like to surprise them with a nitrous kit.
What else do I have to do before adding a nitrous system? How much power do stock 5.0s make and how much would the engine make with a nitrous kit?Jim DurhamWilmington, NC
We just acquired a Fox 5.0 with an AOD, so your timing is good. Keep an eye on this magazine for ideas on how to make your 5.0 a little more lively. Yes, AOD-equipped Fox Mustangs are far from fast in stock form.
For now, you can install a mild 75-100hp nitrous system with no other mods required. A simple dry-nitrous kit from Edelbrock or NOS will add a solid 75-100 hp after an installation that takes about a day. The car should be a full second quicker in the quarter-mile running the squeeze. To leave those T5 cars in the dust, consider adding a set of 3.73 or 4.10 gears in the 8.8-inch rearend. A looser torque converter would be the next most logical upgrade after the nitrous and gears.
Stock, a car like yours makes about 180-190 hp at the rear wheels (it's rated at 225 hp at the flywheel). With the nitrous, look for around 300 hp at the wheels and maybe more with a good tune.
Pushrod To Modular?I own a '94 Mustang GT and want to swap the tired 5.0 for a low-mileage Cobra engine out of a wrecked '99 or '01 Cobra. I would buy the whole package with the engine, computer, wiring, accessories, and transmission.
What difficulties can I expect with this swap, especially concerning fitment and the swap from automatic to manual trans? Steve KeeferPhiladelphia, PA
Difficulties? There would be many. Sometimes I come across as something of a scrooge when it comes to complicated engine swaps, but the fact remains, the goals of a huge project like this can be achieved much more easily, so I will continue to point out ways to achieve those objectives.
Sure, swapping a four-valve Cobra engine into a '94-'95 Mustang can be done, and I know people who've done it. But why would you? To make the car faster, right? If that's the aim, a pushrod 347 will make the car just as fast as any modular Cobra, if not more so. Add a blower to a short-deck stroker and your car will be much faster than with a naturally aspirated Cobra engine. It would run with most blown modulars, too.
The electronics aspect of the swap is monumental. Though I'm no expert in the field of these swaps, I believe you'd have to swap the engine wiring harness from the donor car into your '94. You'd also have to swap to a 4.6 K-member since the two engines are totally different underneath.
As for the trans conversion, you'd obviously be looking at pedals, all the clutch parts, the trans, and who knows what else. Unless you must have a manual trans, go with a beefed-up rebuilt AOD-E, such as the one from Lentech Automatics (613/838-9996, www.lentechautomatics.com).
If your car is fairly nice, it deserves to be retained to some extent in its original condition. SN-95 5.0s (just two years for '94-'95) are unique cars and you could make yours into a real stormer more easily than doing the 4.6 swap, which I guarantee will be filled with landmines. Rather than tear your car apart, start putting together the pieces now for a stout 347 by beginning with a good short-block from one of the many companies that offer them. Add aluminum cylinder heads, available from Edelbrock or AFR, and procure a good EFI manifold such as an Edelbrock Performer RPM II. While you're doing that, your car is still on the road. You could probably even buy an entire 347 crate engine for less money than doing the 4.6 swap.
If you aren't married to your car, it's run down, or you have the itch for a high-tech modular four-valve 4.6, I'd say trade up to a '96-'01 Cobra. A friend of mine sold his nice '99 Cobra last year for only 15 grand, so there are plenty of good Cobra deals out there.
Blower Before New Motor?I have a '94 Mustang GT with several bolt-on updates already on the car, including an exhaust system, 3.73 gears, a 65mm throttle body, headers, and an Edelbrock intake. Although the car has more than 100,000 miles, the engine doesn't use any oil and it runs quite well. I'm thinking about adding a supercharger now and maybe going with a new long-block later. Would supercharger boost be too much at this point for the high-mileage engine?Terry JohnsonSacramento, CA
If you have the budget to swing the blower and a new engine, why put the blower on the old engine? Get the new engine up and running in the car, then add the supercharger later. Although you might be on the borderline with an engine that's led the good life, more than 100,000 miles is still quite a bit. And to minimize downtime with your car, get together as much as you can for the new engine before you take your car apart.
It sounds as if you'll be building a whole new engine and maybe reusing the intake that's on your car now. If your car had fewer than 75,000 miles on it, I'd say you could add the blower now and run it that way until you get the new engine. But at this point, I think you'd save considerable time by getting the new engine in the car first, then installing the supercharger afterward.
Send your '79-'04 Mustang questions to: Late-Model Corral, 3816 Industry Blvd., Lakeland, FL 33811. E-mail to firstname.lastname@example.org with "Late-Model Corral" in the subject line. Please be sure to include your name, city, and state in all letters and e-mails.