Buick Grand National and especially the GNX, but there was little-known Regal-based turbo-six coupe that preceded them.

The 1987 Buick GNX arrived at the end of the muscle car era and immediately made almost everything else on the road look slow ...

This cutaway comparison of a standard 3.8-liter block (left) and a heavy-duty 3.8-liter block (part No. 25500003) reveal thicker main webs, an additional lifter valley rib and heavier pan rails. The H ...

From the March 1999 issue of GM High-Tech Performance: The 1986 and 1987 Buick Regal Grand National set the performance bar high in the 1980s, not with a V-8 but with a turbocharged intercooled V-6.