Michael Johnson Associate Editor
March 1, 2002
Photos By: Matt Decillis
The latest excitement on the Two-Valve front is the Bullitt intake. Of course, as standard equipment on the Bullitt Mustang, the intake brings much improved durability to the table thanks to its aluminum construction. It's not that you would want the Bullitt intake for a huge increase in horsepower (even though it did provide an increase on Jimmy V's car); it's mostly needed because of the factory intake's propensity to crack and create a monstrous vacuum leak. If you're running a power adder on a modular Mustang with a stock plastic intake, you're running on borrowed time. Just ask Vicki Hart, Susan Bodnar, and countless others who have had to replace theirs.

Horse Sense: With the 50-lb/hr injectors Jimmy Vaccaro is running now being maxed out, Jimmy LaRocca wants to try a set 160-lb/hr injectors teamed with an EPEC computer system. With a step up in blower size in the near future and these additions, Jimmy V will be pondering his next round of modifications as he sails down the quarter-mile in nine seconds with his buddy in the Grand National.

We all know the Two-Valve GTs have needed horsepower help since they've been in existence. No secret there-and no need for us to harp on it any longer. The Two-Valve received a healthy boost in 1999 with an injection of 45 hp, but with the Z28 and SS Camaro running more than 300 hp, this still left the GT in catch-up mode.

To weigh the odds more in their favor, many Two-Valvers have strapped on superchargers, while '96-'98 owners have added the '99-up heads and intake (or complete '99-up engines) for increased horsepower. Nitrous hasn't really caught on with the modulars as it did with the pushrod crowd, but that will change with more kits becoming available. In either situation, building horsepower with a Two-Valve modular motor is going to be limited by the plastic intake.

Enter the Bullitt Mustang and its new aluminum intake. Though the rumor mill gave the Bullitt up to 275 hp from a Two-Valve mill, the final tally left 265 hp on the table-just 5 more horsepower than a GT. This horsepower level was definitely a disappointment, but the Bullitt intake has jumpstarted a trend of Two-Valve intake swaps to take advantage of its durable design.

Even with the stock intake in place, Jimmy V's car still made 538 hp and 510 lb-ft of torque at LaRocca's Performance. This figure came courtesy of 15 pounds of boost, but Jimmy LaRocca and Jimmy Chahalis of LaRocca's Performance felt this boost level was the most the plastic intake could hold. Notice the oil-fill location-more on that later.

One of the first contestants on the Bullitt intake game show is Jimmy Vaccaro and his '99 35th Anniversary GT automatic. If anyone's car was to scream for a Bullitt injection, it would be Jimmy's GT. With an ATI/ProCharger D1 supercharger, a built short-block, and an equally stout set of heads, Jimmy's car was capable of 500 hp on Jimmy LaRocca's Dynojet. It was also capable of sending the original 4R70W automatic packin' for the junk heap with a Lentech Strip Terminator going in its place.

The first time out with the plastic intake reaped 10.70s on a mild tune. After switching to the Bullitt intake, those numbers dropped to a 10.32 at 129 mph with Jimmy LaRocca behind the wheel and shifting at 6,800 rpm. With Jimmy V behind the wheel, the car ran a 10.41 at 130 mph shifting at 6,200 rpm. "Jimmy shifts it higher because it ain't his car," Jimmy V joked. With no other changes at a Superstallions of the Net race at Cecil County Dragway in Maryland, Jimmy V ran consecutive 10.87s. However, he accidentally shifted from First to Third on one pass, and the belt tensioner let go at about 1,000 feet, sending the belt in about 10 different directions.

For now, Jimmy is happy with the car. He can drive it anywhere, throw the slicks on it, run 10s, and drive it home. His neighbor with the Grand National respects him now. The gentleman with the Grand National also drives his car to Englishtown, rips off 10.40s, and drives the car home. One of Jimmy's goals is to beat him. He says the guy's a little better driver so he'll have to line up a best out of three with the car in its current state, but for 2002 Jimmy says the guy is "toast." The goal is nines on slicks, driving to and from the track. If we know Jimmy V, it's as good as done.

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Here's an illustration of the two different types of valve covers-or cam covers, in Ford speak-designs. On top is the Romeo-built head, and at the bottom is the Windsor-built head. The two designs simply represent the two different plants at which the engines are built. According to Mike Siska of Magic City Motor Corporation and the owner of a wicked 12-second blown T-bird, before the '01 model year, all modular motors were of a Windsor-build. "Basically, the Windsor plant builds truck engines," Mike says. He also says that for 2001 and future years, the Windsor plant will be building strictly truck engines, while the Romeo plant will build the Two-Valve Mustang 4.6.

There are a couple ways to figure out which engine is under the hood of your Mustang. One is to simply check the VIN. In the eighth-digit position, you should either find a W for a Romeo- built engine or a 6 for a Windsor-built engine. Now, just because your eighth digit is a W, it doesn't always mean it's a Romeo-built engine.

When Roxanne Shepard blew her '99 GT's engine at the '01 Modular Shootout at Rockingham, the new engine she received was a Windsor-built 4.6 with camshaft bearing caps fitted to the heads (think of the bearing caps as you would main bearing caps for the camshaft). The bearing caps are a dead giveaway for a Windsor-built, or truck head. The photo shows the bearing caps of which we speak. These are the heads we used for our '99 head swap article ("Two Steps Forward," Nov. '01, p. 75). They are obviously Windsor-built. The easy way to tell what heads you have is to count your passenger-side valve-cover bolts. If you count 11 bolts, you have Romeo heads. If you count 14 bolts, you have Windsor heads. Clear as mud, right?

Joe Charles of Parkway Ford [(888) FORD-SVT] provided us with a list of components needed and the corresponding part numbers for a Bullitt intake swap. The parts listed are all factory Ford Mustang Bullitt pieces, and if you order the alternator, the corresponding plug will not be included. That's why we are stressing the importance of the PA-Performance kit. PA's kit comes with both the alternator and the plug, and it will retain the Ford alternator bracket. Interestingly enough, Joe tells us the '01-up Romeo-heads are cheaper than the '99-2000 heads, which is good news if you have a '96-'98 Two-Valve prepped for a Bullitt intake swap and you wish to upgrade the heads as well.

Another note to remember: Don't reuse gaskets and bolts that are relatively inexpensive in the first place. Randy Stinchcomb of Universal Ford of Baltimore recommends using new gaskets and bolts to save yourself potential headaches down the road.

With the stock intake, Jimmy V's car belted out 538 hp and 510 lb-ft of torque. After the addition of the Bullitt intake, those numbers rose to 562 and 537, respectively. The horsepower number may not show up here, but the peak is at 6,290 rpm. We just didn't have enough room to show the breakdown in 10-rpm increments. Furthermore, notice the peaks are at a higher rpm with a much broader powerband throughout the range in both horsepower and torque.