Question: what is the difference between a buick grand national and gnx?
Answer: Off the dyno the GNX engine is up 55 bhp from the standard Grand National's rating to 300 at 4400, while torque climbs from 355 to 420 at 2400 rpm. Buick had already reached the limits of the Regal's suspension with the Grand National, so the GNX is beefed up still more.