If the Oldsmobile 4-4-2 is among the best-known muscle cars of its day, the Oldsmobile Cutlass Supreme SX may be among the most obscure. Built in 1970 and 1971 only, the SX package, code Y79, added a 455-cu.in. V-8, the Turbo Hydra-Matic 400 automatic transmission, a rear bumper with exhaust cutouts, and SX badging. The package, which replaced Oldsmobile’s earlier Turnpike Cruiser, was available on Cutlass Supreme two-door hardtop and convertible models only, and the GM brand assembled 7,197 examples in 1970 and 2,177 in 1971. As muscle car prices climbed, SX models grew in price and popularity, and clones became more commonplace.
The owner of this 1971 Oldsmobile Cutlass Supreme SX, for sale on Hemmings.com, identifies it as an authentic Y79 car, as proven by the remains of the original build sheet. An award winner at the 2010 Olds Nationals, the car also benefits from a bit of performance work on the rebuilt 455 and Turbo 400, which should make this an entertaining, yet somewhat under-the-radar, weekend driver. From the seller’s description:
1971 Cutlass Supreme SX. (Production run was a total of 2117 of which 357 were convertibles). This is a true SX, as I found 85% of an original build sheet under the gas tank. The option code for the SX package was Y-79 which I can prove. Best of Class (16B) Olds Nationals, Sturbridge, MA 2010.
Black Bum Exterior, Pearl white interior (spit bench seat) by Legendary Interiors. Black Vinyl top, OAI Hood, SS-III Rally Wheels, BF Goodrich Radial T/A’s (255 60R 15″), P/S, Power Disc brakes, A/C (new expansion valve, receiver Dryer, POA Valve), Original AM/FM (Redi-Rad) converter installed, Rally Pack Gauges, Sport Wheel, Courtesy Lights, Map Light, Glove Box Light, Trunk Light, Remote Trunk Release, 1970 Sport Mirrors, Day/Night mirror, Dash Board redone, New head liner. Period correct Interior and Trunk “Oldsmobile” rubber floor mats.
Rebuilds on numbers matching 455 Engine and Turbo 400 (Kenny Bell 400-2 Shift Kit). Installed a Gear Vendors Overdrive, Rear Differential is a 3:23 Posi (12 Bolt).
I have a separate folder on the engine rebuild, all quality USA parts. Engine bored .030 over, mild Comp cam, Johnson Hylift lifters, Seal Power Pistons, new push rods, valve springs, Cloyes Timing chain set, Melling oil pump, Crankshaft is a Nodular Crank p/n 397363 ( Large “N”on front Counterweight). Petronix III Electronic Ignition (Distributor pick-up, Coil and 8MM Wires), Distributor has been re-curved. New; Head bolts, Intake bolts, Exhaust Manifold bolts, Front cover and bolts. Correct W/Z Exhaust manifolds. Carburetor has been Re-done by All American Carburetor, correct part number/ date to production run of the car.
Engine compartment and Trunk re-wired with American Auto Wire products. Brake System completely rebuilt, (all lines by In-Line Tube, Proportioning valve, rear Cylinders, Front Calipers, Booster and Master Cylinder). Front Suspension has new Upper/Lower Control Arms, New shocks.
Power Steering Gear Box and Pump Rebuilt by (Power Steering Services, Springfield MO), close ratio 12:1. Correct Modine Radiator, Correct Coolant Recovery Tank, Battery replaced with a Class 27 Delco.
Bumpers have been replaced, all trim has been Straightened I Polished or replaced. T-3 Head lights by American Auto Wire, and a new fuel tank sender.
Notes: Engine mileage approximately 700 mile’s, Transmission approximately 5,600 miles, Overdrive unit approximately 3,800 miles. The complete OAI air cleaner assembly is also offered with the vehicle.
Kernersville, North Carolina
Find more Oldsmobiles for sale on Hemmings.com.