1970 Oldsmobile Cutlass W-31

The W-31 was a Cutlass with a 350 CID Performance Option, not a 442 Option and was only built for 2 seasons, in 1969 and 1970. Engine upgrades included the use of what's become known as the 308 camshaft, which was actually the unit's duration; the camshaft also touted .474-inch lift and an intake/exhaust valve overlap of 82 degrees. The engines were factory blue printed units by picking components off the production line that were matched in weight. The Connecting rods for the W-31 engine were particular to the engine The Cylinder heads were also specific to the W-31  Completing the fuel/air induction system was an aluminum intake manifold with a "performance calibrated" 750-CFM Rochester Quadrajet as well as the W25 low-restriction air cleaner assembly. Above that was a new-for-1970 air induction system: twin scoops on top of a fiberglass hood with chrome hold-downs.

Only 1029 of these made. The rarest of the high performance Oldsmobile made.
Behind the engine is a Muncie M21 4 Speed Trans w/ Hurst Shifter. Dual Exhaust, RLimited Slip Rear-End. Manual Brakes, HD 4 core Radiator. the W-31 package automatically upgraded the front and rear coil-sprung suspension to the FE2 heavy-duty components, including special springs and tubular hydraulic shocks.