well the classes can verry depending on what area your in. but generally the main limitation starts with the size of the inlet on the turbo charger.
around here there is
2.4 work stock- 2.4 inducers on the turbo, no suspention blocks, stock drive train, factopry apearing engine, no water,dot aproved tires. basicly a beginner class for guys that want to pull there daily drivers
2.6 modified street - 2.6 inducer. block are allowed but mush have 2in, of travel, factory availabe drive train in a 1ton or smaller truck, no water dot tires. truck must still be street legal, but not nessicarily practical to drive on the street.
3.0 pro stock. 3.0 inducer turbo. water is allowed, open drive line, and dot approved tires
there are also many other classes around but I'm not shure on the rules enough to explain them
2.5, 2.8, unlimited single, super street, modified, and I'm shure there are more
you might look in the "pulling organization" thread up in the stickey section and se if there is a sanction in your and check out there rules. that will give you a lot better explination of all the rules.
2.6 modified street pulling truck "The Lone Stroke" My Videos
1996 f350, powerstroke, 4x4, 5-speed, 4.56 gears, Swamps 450/600 injectors, Swamps BFH turbo, Swamps Idm, Swamps tunes, BTS oil, SBC clutch, studs, springs, tubes, air to water intercooler, fuel system, factory rods!
1997 f350, srw, reg cab, 4x4, 5 speed, 4.10 gears, 3in down pipe, straight pipe, mystery chip.
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