How many cubes can you stuff into a midyear Corvette before you say enough is enough? 350? 396? 454?
What if we let you in on the inside story of a red-on-red, previous NCRS winner '66 Corvette coupe that's now stuffed with 572 cubic inches of pure GM big-block power?
"I bought my '66 Corvette to go fast, but I was disappointed in its performance," Leroy Gonzalez, a shopping-center developer in Seffner, Florida, tells VETTE. "That's why it's now powered by a GM Performance Parts 572/620hp big-block."
The '66 Corvette was the fourth year of the marque's second generation. A total of 9,958 coupes and 17,762 convertibles were built, for a production total of 27,720 units. Of these, 9,755, like Leroy's, were optioned with the base-model 327/300hp Chevy small-block engine.
To transform his mediocre-mill midyear into a maniacally meteoric missile, Gonzalez put out a call to AntiVenom, a Corvette performance shop also in Seffner. "Leroy came to me and didn't know what he wanted to do with his Corvette," Greg Lovell, the shop's owner explains. "I offered to transplant a 505hp LS7 into the car, but he thought it wasn't impressive enough. He said that it had already been done many times in the hobby; instead he wanted something brutal, flashy, and intimidating."
After doing his research, Lovell decided the most impressive, yet streetable, crate engine offered by GM was the Deluxe 572/620. "When I saw it described in the GM Performance Parts (GMPP) catalog as 'the coolest collection of orange, chrome, and aluminum you've ever seen,' I knew it was the right motor for this Vette. The 620 hp and 650 lb-ft of torque sure didn't hurt our decision either," he says.
Dr. Jamie Meyer, GM Performance Parts Marketing Manager, agrees. "This is flat-out the baddest street Rat available that still happily runs on pump gas. Everything was designed to offer you the ultimate big-block experience. That's why we've given it the title 'King of the Street.'"
GMPP ships the Deluxe 572/620 crate engine turnkey, meaning it includes a single-plane aluminum intake, a Demon 850-cfm carb, Chevy-script valve covers, an electronic distributor, spark plugs and wires, an oil pan, and a starter. The buyer just has to add engine accessories, pulleys, and brackets. It features a cast-iron block with four-bolt mains, a 4.560-inch bore, a 4.365-inch forged-steel crank, shot-peened forged-steel connecting rods, and forged-aluminum pistons. It's topped with aluminum, rectangular-port heads with 112cc combustion chambers, 2.25/1.88-inch stainless steel valves, and 1.7:1 aluminum roller rockers. A 254/264-degree-duration hydraulic roller cam with 0.632/0.632-inch lift actuates the valvetrain, and compression sits at a premium-friendly 9.6:1.
To propel the transformation, Lovell removed the Corvette's original, numbers-matching 327/300 and bagged it for safekeeping. Then, confronted with the task of making the 572, its engine accessories, and the requisite cooling and braking hardware all fit within the close spaces of the Corvette's engine bay, he got to work.
"Physically, the 572 will bolt right into place in a midyear Corvette," Lovell says. "However, the factory-supplied oil pan comes extremely close to the ground; I swapped it out for a Milodon unit."
There were other challenges, too. "There was no room left for a GM power-steering reservoir or vacuum-assist power brakes. I had to hunt for a junkyard-jewel reservoir that would fit, and extracted one from a Lexus. A Hydroboost system met our space requirements, but just barely," he laughs. "In addition, I couldn't locate any off-the-shelf headers to mate up to the 572. Luckily, I was able to modify a set of Stainless Works '63-'82 big-block headers for clearance around the steering box."