We spoke to SDPC's Tim Cooks about the company's custom-order LS short-blocks. "Our 402, 416, and 427 packages are really good performers and [are] heavy duty," Tim told us. "Spada's 402 is based on a GM LS2 aluminum block with a 4.005 bore and a 4.00 stroke. The rotating assembly...[uses] a Callies forged crank and Diamond pistons manufactured with a 2618 HD forging and topped at 14 cc. Callies Compstar H-beam connecting rods [are] held in place with ARP bolts. We balanced the entire rotating assembly before we shipped it. Because these packages are custom-ordered, we can supply, install, and balance whatever components the customer prefers. Eagle, Manley, and Lunati are some examples."
Once the short-block arrived in Florida, Spada arranged for Michael Huser of Tampa-based Chevy MD to perform the installation. According to Michael, dropping the newer-generation block into the C5 posed some specific challenges. "The 402 had arrived with knock-sensor-relocation wiring. I relocated the sensors to the two empty holes on the passenger side of the block, near the motor-mount holes. I also had to trim away at the motor-mount bracket on the passenger side, which allowed the LS2 block to sit flat in the Vette's subframe. The cam sensor on the LS2-based 402 was different as well. We had to use a timing-gear set for the LS2 and run the Vette's ECU cam sensor off the LS2 timing cover."
The induction system comprises a ported version of the same FAST 90mm intake and a Comtech 90mm throttle body. Racetronix 42-lb fuel injectors squirt fuel delivered by the stock GM fuel pump, while MSD coil packs and wires team with NGK iridium plugs to light the mixture.
A GM T56 transmission with hardened output shafts handles the shifts. The clutch is a C6 Z06 assembly, paired with a factory LS6 flywheel and slave cylinder. Somewhat surprisingly, the differential remains stock and is still loaded with the original 3.42 gears.
The suspension has been upgraded at all four corners with QA1 adjustable shocks. Lightweight CCW SP550 wheels wrapped in BFG rubber shear a few pounds and contribute to the Vette's race-ready appearance.
If there's one thing a son learns from his drag-racing father, it's that the lighter the vehicle is, the quicker the e.t. will be. So Andrew got to work. He pulled the Corvette's entire A/C and heating assemblies. He removed all of the climate-control ductwork and replaced the fiberglass stock hood with a carbon-fiber alternative. Since our photo shoot, he's gutted the power-window regulators, motors, wires, and switches and replaced the glass windshield and door windows with riveted-in-place and slider-controlled Lexan polycarbonate sheets.
Even that wasn't enough. Andrew purchased a carbon-fiber racing battery from Braille Auto of Sarasota, removing another 27 pounds of weight from the Vette. He replaced the factory starter with an AeroSpace lightweight unit and saved another 11 pounds. He pulled the Z06's leather-clad thrones and bolted in AeroSpace racing seats good for 40 pounds of weight reduction. While he was at AeroSpace, he also picked out lightweight brake components, saving the Vette 24 pounds in the front and 31 pounds in the rear. Even the factory steering wheel was tossed aside in favor of a Sparco racing unit.
All in all, the Vette was lightened 326 pounds, giving it a race weight of only 2,990 pounds-with Spada at the wheel. Factor in a chassis-dyno-verified output of 552 hp and 501 lb-ft, and Andrew says the car is good for 10.30 e.t.'s at 133 mph.
Future plans for the Vette include CNC-ported L92 heads and an APS twin-turbo kit. Spada's idea is to run 15 psi of boost and pull 960 hp/750 lb-ft with his next combo. Cylinder-head guru Pete Incaudo says Spada might even follow his advice and push the boost to 22 psi on a reduced 8:1 compression ratio.
But that's for a future article. For now, engine installer Michael Huser sums up Spada's 402-cube Z06 thus: "It's a solid, strong daily driver. I think you could drive it to Disneyland and take your girlfriend with you too."
Disneyland? Do they have a sanctioned quarter-mile track? We'll have to get back in touch with Andrew Spada and let you know.