Metric Chassis 

The General Motors G-Body platform (1978-88 Chevy Monte Carlo, Buick Regal, Pontiac Grand Prix, Oldsmobile Cutlass). "Metric Chassis" is the name given to these cars by dirt track racing enthusiasts because they were the first GM car to start using metric fasteners.

Tom is running a metric chassis but most others have a Camaro at that track.

Metric Chassis by metric car August 13, 2012