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1971 Supercharged Buick GS

A Force-Fed 455 To Challenge All Comers

Photography by Terry McGean

Tech Notes

What: '71 Buick GS 455

Owner: Nathaniel David Durell

Hometown: Ramona, California, the sticks of San Diego

Engine: The numbers-matching block was stashed while another '71 455 block was bored 0.030-inch, de-burred, decked, and drilled and tapped for additional head studs. The stock crank was turned 0.010-under and swings Crower Sportsman rods with JE custom pistons that make 8.74:1 compression.

Heads: Thanks to TA Performance in Scottsdale, Arizona, even Buick guys can get aluminum heads. David started with TA's Stage 2 Street Eliminator assemblies with 2.12/1.81-inch valves and then had Buick head-porting guru Greg Gessler work them over until they flowed 317 cfm on the intake side at 0.500-inch lift.

Camshaft: David didn't want us to reveal the specs, but we can allow that the custom Crower grind is a surprisingly tame, hydraulic, flat-tappet unit, particularly for a 462-inch engine. We'll say this: The intake duration is under 240 at 0.050, and the lift barely cracks 0.500-inch.

Induction: Here's where it gets interesting. The intake is a single-plane from TA Performance to match its heads, but forcing the atmosphere in is a Vortech YS-trim centrifugal supercharger. It blows into an enclosure surrounding a Holley 850-cfm double-pumper; a pair of Holley electric "black" pumps keeps it fed. The blower mount was designed and fabricated by Greg "Driver" Sadeau of GES Engineering in San Diego.

Exhaust: A set of Jet-Hot-coated TA Performance headers with 211/48-inch primaries and 311/42-inch collectors feeds into a custom 311/42-inch system that terminates just before the axle with a pair of Race Magnum "bullet" mufflers. In spite of this, the Buick really isn't that loud.

Transmission: The '71 Buick Turbo 400 was built by DRW Transmission in Santee, California, and fitted with a 3,200-rpm, 10-inch converter from Art Carr. Hanging off the back is a Gear Vendors overdrive unit, providing 0.78:1 in any gear at the touch of a button.

Rearend: The rearend is still the original 8.5-inch "corporate" axle assembly with 3.73:1 gears and even the stock axle shafts. A TA Performance aluminum support cover helps keep the guts inside.

Suspension: Up front, the Buick remains basically stock right down to the springs, though the sway bar is gone and a set of Competition Engineering 90/10 drag shocks has been added. In the rear, BMR lower control arms work with stock uppers mounted to "no-hop" brackets to locate the axle. Each stock rear spring has an airbag inside, and QA1 shocks provide tunability.

Brakes: Stock front disc/rear drum brakes remain in service.

Wheels/tires: Weld Draglites are used at all times: 15x5-inch in front mounting 205/70-15 tires and 15x8-inch in the rear with Mickey Thompson ET Streets in 28x12.5-15 for the street.Another pair of 15x8 Draglites mounts Hoosier 29x10.5W-15 slicks for serious track days.

Body: When David bought the Buick, it was wearing a black-and-white, '70 GSX paint scheme, but in time it was returned to its factory hue of Burnished Cinnamon. The original ram-air hood is stored, while a standard Skylark hood was modified to accept the repro Stage 2 scoop. The GSX wing on the trunk is also repro.

Interior: Everything that the Buick left the factory with is still inside the car, along with a six-point rollbar and a Precision Performance Products shifter on a custom bracket.

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