10/13/2026
Same company. Same year. Same displacement. Two engines that share nothing at all.
Oldsmobile went the way the textbook says. A 4.25 inch stroke, the longest of any GM 455, on a tall block. Longer stroke means more leverage on the crankshaft, and leverage means torque. The W-30 made 500 lb-ft and 370 horsepower.
Buick did the opposite. They kept the 3.90 inch stroke from their smaller engines and opened the bore to 4.31 inches instead, the biggest of the group.
By the usual reasoning that should have made less torque.
It made more. Five hundred and ten lb-ft, which was the highest figure anybody in Detroit advertised that year, and it arrived at 2,800 RPM, eight hundred revolutions before the Oldsmobile got to its peak.
Here is why, and it is worth understanding because the long stroke myth never dies.
Torque comes from how completely you fill the cylinder, not from the stroke on its own. A bigger bore leaves room for bigger valves, and Buick used 2.125 inch intakes in the Stage 1 fed by a deliberately modest port that kept the air moving fast. Fill the cylinder early and the torque arrives early.
The Buick was also the lighter engine, because the block used thin wall castings.
Oldsmobile sold the W-30 to people who wanted a muscle car. Buick sold the Stage 1 to people who already owned a heavy, comfortable car and wanted it to move.
A Stage 1 GS ran low thirteens and would take a Hemi car on if the driver was good.
