Our first official Mustang project car left the stable in 2004 – as luck would have it just in time to celebrate our new early Mustang catalog. Ok, so it was planned that way. Anyway, following YearOne tradition, our plan for the pony was to leave the basic fastback body alone while the running gear and interior was upgraded to a more modern specification. Our cars typically spend a bunch of time on the road and the track, so upgrading the suspension system, brakes, powertrain and interior really improves their behavior on both.
Once again following YearOne tradition, we planned on incorporating technology from a late-model Mustang into our early car. Specifically, we wanted to use as many bits from the then-just-released 2003 Cobra as we could. The ’03 Cobra got the full treatment from Ford, with a healthy supercharged DOHC 32-valve 4.6 liter engine churning out 390 horsepower in stock trim, a strong 6-speed transmission, and an independent rear suspension.
The ’66 GT we started with was a solid car that had been restored quite a few years back. Upon disassembly we were pleased to see the basic body shell was in very good condition, which meant the amount of initial prep work needed to provide a solid foundation for the project would be minimal. This isn’t usually the way it works for us; usually we start with very rough cars and spend a ton of time getting the basic platform into some kind of usable condition. We stripped the car completely and addressed the few areas that needed attention.
Then the fun started. Our plan was to install the supercharged 4.6, six speed and independent rear into the ’66 body. Sounds good on paper, right? Once we broke out the tape measure, we realized that stuff wasn’t exactly going to fall into place. We anticipated having to cut the shock towers out of the front, and included a Martz front subframe and suspension setup in our initial plan. It was the rear that was going to cause the most trouble. Mounting the IRS wasn’t really the problem, it was the overall width of the assembly that gave us indigestion. There was no way to get the wheels and tires inside the quarter panels without resorting to flares (which we really didn’t want), or narrowing the halfshafts and control arms (which we really, REALLY didn’t want). So, to make a long story short, we punted. We decided a 9-inch housing with a four-link and coil overs was a pretty good rear setup after all.
Using the Martz front subframe in the car not only made room for the wide mod motor, it also gave us modern geometry with tubular controls arms and a wide range of adjustability. Out back, a Martz adjustable four-link setup also let us fine-tune the rear suspension. Coil-overs all the way around add ride-height adjustment, and made spring rate changes a quick and simple matter.
The supercharged 4.6 Cobra engine is a stout piece straight from Ford. It features forged pistons, Manley H-beam rods and a forged crankshaft spinning in cross-bolted mains. The factory package is underrated at 390 horsepower, which is good, but of course we wanted a bit more. So we added a Kenne-Bell screw-type supercharger with a Metco Billet pulley arrangement to allow quick boost adjustments. We also built a set of headers using Stainless Works tubes, and fabbed up our own throttle-body setup that lets us use a cool vintage Cobra air cleaner arrangement. We painted the block Ford blue, left the heads bare aluminum, and painted the cam covers with black wrinkle paint, again to give a nice vintage look to the modern powerplant.
Behind the engine is an ’03 Cobra-spec Tremec 6-speed with Ram supplying the clutch. Clutch linkage is from Pro-Motion, who makes a conversion setup for these cars. The rear axle is a Moser 9-inch unit with a Detroit Tru-Trac limited slip and 3.73 gears.
Body mods were kept to a minimum, as you can see from the images. The biggest change has to be the old-school Thunderbolt hood – made in very new-school carbon fiber! Talk about old-meeting-new. The hood is light, of course, and we’ve since changed to a hinged carbon fiber version since the car was first completed. The color is late-model Mach 1 Azure blue, with an eggshell black upper that blends well with the carbon hood. Various other bits were given the black treatment, just because.
Wheels are Budnik Famoso billets, 17″x7″ front and 18″x10″ rear, wrapped as always with BFGoodrich g-Force rubber. Brakes are from Stainless Steel Brakes Corp., and feature 13″ rotors front and rear grabbed by 4-piston calipers.
Inside the car we worked over a set of Fox body Mustang seats and covered them in black leather with blue cloth inserts. The door panels match the seats, while the rear is taken up by roll cage and stereo. We worked the dash area over pretty well, and filled it full of Auto Meter Cobalt gauges that glow a cool blue at night.
The car is a beast, especially with race gas and 21-lbs of boost. It’s run the quarter deep in the 11s with this setup on drag radials, but traction is always an issue. For pump gas, we keep the boost down to a more reasonable 14 lbs.
2003 Ford Cobra DOHC 4.6L Supercharged
8.5:1 forged pistons (OEM)
Manley H-beam forged rods (OEM)
Forged crank (OEM)
Custom aluminum heat exchanger
AccuFab 1700cfm throttle body
Metco Motorsports 10-rib pulleys
Stainless Works headers/exhaust
FAST fuel injection system
Be Cool aluminum radiator
Be Cool/SPAL electric fans
Ram single-disc clutch/pressure plate
Ram Aluminum flywheel
Kirban billet shifter
DynaTech aluminum driveshaft
Moser 9-inch housing
Detroit Tru-Trac differential
3.73 Motive gearset
Adjustable tubular control arms
QA1 aluminum coil over shocks
2004 Mach I Azure Blue
YearOne carbon fiber hood
Fiberglass quarter end caps
Fiberglass deck lid
Budnik Famoso Billet
BFGoodrich g-Force KDW
Fuel Safe fuel cell
Holley 255 lph in-tank pumps (2)
Aeromotive fuel rails
Holley 50-lb injectors
Martz tubular front subframe
Adjustable tubular control arms
QA1 aluminum coil over shocks
Stainless Steel Brakes Corp.
4-piston front/rear calipers
13″ rotors front/rear
AutoMeter Cobalt Series