The old-school vibe underhood...
The old-school vibe underhood required painstaking efforts to achieve. Beneath the custom air cleaner is a Schwartz-built adapter that mates the MAF sensor and throttle-body to the GMPP single-plane LS7 manifold. The unsightly stock ignition coils are hidden inside a custom "double-deck" valve cover design. To fit the air cleaner beneath the stock hood, the motor mounts were lowered several inches.
Not wanting to hack up a rare 442, Jeff tracked down a less-desirable Cutlass SX and got to work. "The SX was more of a business man's Cutlass in the '70s, which I thought suited the car's subdued nature very well, and it has a very unique C-pillar compared to other Cutlass trim levels. Of all the A-bodies of this vintage, the SX has some of the most unique body lines," Jeff opines. Since the car had already been restored years earlier, the only metalwork that needed to be performed was patching the quarters and fenders. Although the original 455 big-block and TH400 trans were in good working order, Jeff had more grandiose plans in mind to complete the powertrain makeover. "I thought it would be cool to stroke an LS7 crate motor to 455 ci using the same 4.125x4.250-inch bore and stroke dimensions as the original Olds big-block. Getting the 4.250-inch Eagle crank to fit was quite a chore. I spent countless hours on the lathe and mill turning down the counterweights so that they'd clear the bottom of the custom Wiseco pistons. I had to massage the small ends of the stock rods for clearance as well," he says.
In order to maintain a near-stock appearance in the engine bay, Jeff fitted a single-plane GMPP intake manifold to lightly massaged factory LS7 cylinder heads. The truly trick part, however, is a custom spacer that adapts the stock MAF sensor and drive-by-wire throttle-body on top of the plenum. The end product is a stock EFI system using the original electronics that's neatly hidden under a carb air cleaner assembly. Matched with a COMP 232/242-at-0.050 hydraulic roller cam, the combo is good for 600 hp and 580 lb-ft of torque. "The displacement figure of 455 is partly for nostalgia, but increasing the LS7's stroke by a quarter-inch gives the motor a torquey feel reminiscent of a 455 big-block Olds," Jeff explains. Torque splitting duties are handled by a Tremec T56 six-speed trans fortified with Dodge Viper internals. Out back is a Winters 9-inch floater rearend with an aluminum center section, and freeway-friendly 3.50:1 gears.
Given Jeff's road racing background and the cornering prowess of his prior concoctions, straight-line performance is just one of the Cutlass' many talents. The underpinnings hidden beneath the body are arguably even more impressive than what's underhood. Jeff started his own shop, Schwartz Performance (www.schwartzperformace.com), in 2005 after working for 26 years as an industrial machinist. Combining his expertise as a racer and machinist, Jeff designed a line of custom bolt-in frames for A-bodies, F-bodies, C1 Corvettes, and Mustangs. Naturally, building the Cutlass served as an opportunity to showcase his state-of-the-art frames to the public. The setup features mandrel-bent rails, custom tubular control arms and coilovers at the corners, revised suspension geometry, enhanced tire clearance, splined sway bars, and vastly improved stiffness. "Not only are our frames 125 pounds lighter than stock, they're also 200 percent stiffer in torsional rigidity," says Jeff. "In stock form, the Cutlass could only manage 0.76g on the skidpad. With our frame and suspension setup, it now pulls 1.08g on regular street tires." With the corner-exit and straightaway speeds made possible by all that grip and power, the Olds relies on 14-inch Baer brakes clamped by six-piston calipers to slow things down before the next apex.