AutoX’ing Steed: Gregg Biddlingmeier’s 1988 Ford Mustang


A clean engine bay takes hard work and some careful thought.

If you’re looking at that engine bay and wondering why it looks so clean, that’s because all the wiring that would go under hood has been hidden while the rest of the bay has been smoothed out. With this car participating in the Optima Ultimate Street Car Association series, it must look good for the Design and Engineering section of the competition as well as retain some creature comforts like a radio and heat and air elements, though it is without A/C now.


Yes, it's a 5.0 but with a Holley carburetor and GT40P heads.

That engine is obviously nowhere near stock, but it is a Ford five-liter 302-CI V8. It features a set of GT40P heads, which are the best factory-designed heads for the five-liters in existence, well if you don’t count the Ford Racing GT40X aluminum heads. They come from the 1997 to 2001 Explorer (1996 models had the GT40 heads), and feature a 60cc combustion chamber and a 145cc intake port with 1.85-inch intake and 1.46-inch exhaust valves. The spark plug hole is designed to move the electrode closer to the center of the combustion chamber for a better fuel burn and increased efficiency over the E7TE and GT40 heads. For that reason, though, you must use a header specific to the GT40P.


Cool air feeds in from the custom carburetor undertray and cowl holes cut into the firewall.

The camshaft is a Ford Racing B303 Hydraulic Roller Cam which features a 224-degree duration at .050-inch lift on intake and exhaust, lobe separation angle of 112-degrees, and .480-inch of lift on the intake and exhaust. Well, that lift number is for the stock 1.6 ratio rockers. In its place on this engine is a set of Crane 1.7 ratio Roller Rockers with matching Beehive Springs converts that lift number to .510-inches.


When you're pulling in more air than stock, you need a larger carburetor and a Holley 750-CFM feeds that need.

Up top is a Wieand Stealth Intake with a 750-CFM Holley Carburetor. The Stealth Intake features a 1.83-inch port height and a 1.02-inch width. Even as a high-rise, dual plane design, it’s only 5.59-inches at its tallest and allows the use of the stock hood. The carburetor is sealed by a custom under tray that pulls air from the cowl by the five holes cut into the firewall. Of course, once all that air and fuel get used up, it must go out of the BBK Full-Length Headers with 1-5/8-inch primaries that feed into 2-1/2-inch Black Widow Widowmaker mufflers.


Hurst shifter and a Pioneer Radio; do you need more in a trackable street car?

The transmission is a variant of the T5 5-speeds based on the original Borg-Warner design from Tremec known as the T5Z. It’s stronger than the “World Class” versions with upgraded gear materials, carbon fiber blocker ring lining, and the pocket bearing went from needle to tapered roller along with the World Class improvements over the T5. This was all for increased strength up to an advertised 330-ft/lbs. It also features a 2.95/1.94/1.34/1.00/0.63 gear set.

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