NSPA - The Premiere Sled Pulling Assocition

COMPETITION CLASS	EXHIBITION CLASSES
Trucks - Diesel
Work Stock	Meduim-Duty Hauler
Street
Super Street
Modified	Modified Rear-Wheel Drive Puller / Outlaw Diesel
Stock Semi
Modified Semi
Trucks - Alcohol or Gas
Super Stock 4-Wheel Drive (pump fuel, up to 475cid)
Modified 4-Wheel Drive ( naturally aspirated)
Super Modified 4-Wheel Drive ( blown)
2-Wheel Drive
Tractors
Super Stock Diesel
Modified (multi-engine, blown alcohol)

The NSPA Requires Every Driver, in every Class to wear DOT Approved Helmets.