Engine & Drivetrain
Built back before big-block–sized Gen III motors were the norm, the 383ci LS6 in Mac’s Tri-Five packs a big punch out of a small package. Since iron liners in factory 5.7L LS blocks can’t be bored much at all, the LS6 was cleaned up to 3.905 inches, then stroked with a 4.000-inch Eagle forged crank. The balance of the rotating assembly consists of Eagle 6.200-inch steel rods and forged 11.54:1 JE pistons. Air enters through a stock LS6 throttle body and intake manifold before being routed through lightly massaged factory “243” head castings. A COMP 222/222-at-0.050 hydraulic roller cam with 0.583/0.583-inch lift knocks the valves open, and COMP lifters, beehive valvesprings, 1.75:1 rockers, and titanium retainers ensure precise actuation. Exhaust exits through 1.75-inch Street and Performance headers, a custom X-pipe, and dual 2.5-inch MagnaFlow mufflers. To stay cool in the Texas heat, the 383 utilizes a Meziere electric water pump, a Ron Davis radiator, and a SPAL fan. Built and tuned by Superior Automotive, the stroked LS6 cranks out 520 hp at 5,700 rpm, and 531 lb-ft of torque at 4,400 rpm. Backing up the Gen III mill is a 4L65E automatic, which routes power to a Currie 9-inch rearend fortified with 31-spline axles, 4.11:1 gears, and an Eaton Posi.
The Tri-Five’s underpinnings are part Pro Touring and part cruiser. The front suspension has been rebuilt using springs, shocks, bushings, sway bar, and 2-inch drop spindles from Classic Performance Products. Walton Fabrication welded reinforcement plates to the stock frame and control arms. For accurate directional changes, the tired stock steering box was replaced with a power Borgeson “605” unit. The custom four-link rear suspension is also from Walton, and has been matched up with Alden coilovers that provide a 4-inch drop. The four-link arrangement attaches to the chassis using a trick custom crossmember. The entire undercarriage has been powdercoated and ceramic coated to a gleaming finish.
It takes a trained eye to spot all the body tweaks, but even if you can’t put your finger on all of them, the end product is plenty hot. The front bumper has been flipped upside down, filled, smoothed, and reshaped to follow the contours of the front clip. It’s complemented by a billet front grille. Nearly all the trim has been removed and filled, and the door handles and trunk got the shave treatment as well. Out back is a filled and smoothed Nomad rear bumper. The two-tone paint scheme is a combination of GM Tainted Silver and ’05 Corvette White. Cypress Auto Body (Hawaiian Gardens, California) laid down the hues the first time around, and Painthouse (Cypress, Texas) freshened it up with a new layer of clearcoat a few years later.
Wheels, Tires, Brakes
Thanks to the extra clearance provided by the custom frame, the rear tubs swallow up 20x10 Intro V-Rod wheels while the front end makes do with 18x8s. They’re covered in Nitto 225/40ZR18 tires up front, and 295/40ZR20s out back. Slowing down the brick are CPP disc brakes at every corner. At 11 inches in the front and 10 inches in the rear, they’re not overly pretentious, yet get the job done given the Tri-Five’s street cruising intentions.
A stock Tri-Five interior is already way cool, but Mac made it even better. Elegance Interiors (Upland, California) designed a completely custom cabin. Front and center is a custom gauge panel from Classic Instruments and a Billet Specialties steering wheel. The seats—covered in two-tone gray leather—are out of a Lexus, and feature modern three-point belts. The leather-covered center stack is a custom piece and houses the controls for a Vintage Air A/C system. Tunes come courtesy of a Pioneer stereo system. The custom back seats look just as cool as the fronts, and the floor is covered in German square-weave wool. CHP