Turning a base-model Corvette into a supercharged, big-block behemoth is a dream come true for Jay Adams, a 35-year-old contractor from Mobile, Alabama. We recently ran into the car at this year's YearOne Experience, where it was making its public debut.
"My passion for Corvettes started at an early age," Adams recalls. "When I was three years old, my dad purchased a '70 LT-1 convertible Corvette. From the very first time I saw the car, I was totally fascinated. I thought it was the baddest thing on wheels I had ever seen. I would sit for hours in the Corvette, pretending I was driving it, making engine sounds with my voice as I toyed with the gear shifter. From that moment on, I was a Corvette addict."
Adams passed his grade-school days poring over the latest issues of VETTE, reading about high-performance Corvettes. It was then that he learned about the legendary ZL1-the race-spec, aluminum-block 427 that found its way into two production Corvettes in 1969. "This combo, with a few mods, headers, and a good tune, was worth well over 500 hp and would propel a C3 shark into the 10s," Adams says. "I knew I had to go in this direction when it was time to build my very own Corvette."
In 1996, Adams began a five-year project to restore his dad's LT-1. With that job successfully completed, he decided he had developed the skills required to build his big-block dream car. Five more years passed before he began the project. "In 2006, my friend Don Brooks offered me a '72 Corvette coupe for a decent price, but it needed a full restoration," Adams says. "The car was trashed cosmetically. The T-tops leaked, and rain had filled the interior with water. The seat frames were rusted, and most of the interior was covered with mold and mildew. But the overall condition of the frame and body was very good; there was hardly any rust or corrosion on the chassis or the structural parts of the body. The engine was a non-original 350, [so] I immediately thought back to my dream of building a ZL1."
Realizing that he was on a tight time schedule to make it to the '08 YearOne event, Adams commenced the disassembly, spending three laborious weeks stripping and cleaning the Vette. Then, he removed the body from its chassis and delivered it to Willie Byrd of Mobile, Alabama, who sanded the shell laser-straight. Byrd then sprayed the car with PPG K 36 Prima Urethane Primer Surfacer, followed by PPG Deltron (DBC) 2000 Silver Poly Basecoat and PPG DPU 2021 Concept 2021 Clear.
Meanwhile, Adams went to work on the Vette's new powerplant, starting with a GM Performance Parts ZL1 aluminum block (PN 1237085). Since Chevy's 427 and 454 engines share a bore size of 4.25 inches, he decided to up the ZL1's ante to 454 ci by outfitting it with a GMPP 4.00-inch forged crankshaft (PN 3963524), 6.135-inch Crower rods, and JE blower pistons. GM aluminum oval-port aluminum heads (PN 12363390) feature a 290cc runner volume, semi-open combustion chambers, heavy-duty pushrods, roller lifters, 2.25/1.88 valves, and high-performance valve springs. A Crane custom-grind cam orchestrates a fortissimo valvetrain symphony with 226/234-degrees duration, 0.587/0.610-inch lift, and a 112-degree lobe-separation angle. The melody is accented by Hedman Hedders and a 21/2-inch custom exhaust with 3-inch QTP cutouts. For reasons that will soon become clear, the compression ratio is a tame 8.5:1.
Instead of fiddling with carburetion, Adams installed a modern fuel-delivery system: a FAST XFI with an Accufab 4150 throttle body, Edelbrock fuel rails, Siemens 65-lb/hr injectors, an Aeromotive fuel-pressure regulator, and an Edelbrock Victor Jr. EFI intake manifold. Ignition, however, remains traditional: an MSD 6AL box and ACCEL dual-synch distributor routed with Packard 8mm wires to AC Delco R43XLS plugs.