[Mike Carr]

The '71 Dodge Dart 2 door Swinger, 318 cid, 230 factory rated car has been de-rated, by NHRA, to 185. The natural weight break of the car is 15.64, making it a natural O/SA (15.00-15.99 pounds per HP). It can also run N (14.50-14.99) and P (16.00-16.99). A car can use the "top" weight break to determine the mnimum weight in each Class. Class weight break, multiplied by the NHRA rating of the engine, plus 170 pounds for driver, equals minimum weight, with driver, across the scales.

N/SA is 14.50 x 185 +170 = 2,852.5 pounds
O/SA is 15 x 185 + 170 = 2,945
P/SA is 16 x 185 + 170 = 3,130

Even if you weigh less than 170, you will have to add ballast to meet the Min Wt for each Class. Same if you are heavier than 170, you can remove ballast. But the car, with driver at the conclusion of the run, must be the weights listed above for it's respective class.

You qualify against your Class Index. The further under the Index you are, the higher up on the qualifying sheet you are. Once qualifying is over, cars are laddered on a Sportsman Ladder, where the top half is matched against the bottom half. Meaning, 1 vs 33, 2 vs 34, down to 32 vs 64, in a 64 car field. In Eliminations, all cars will dial-in, and the race is run with bracket racing rules, if the cars are in different classes (N/SA vs A/SA, for example). All cars MUST dial in at their Class Index or quicker, even they can not go that fast. So performance is important. If two cars of the same class race (N/SA vs N/SA, A/SA vs A/SA, etc), the race is run heads-up, no breakout, first to the finish line wins. So performance is doubly important.

As far as highlighted material, I haven't looked at the new, online NHRA Rulebook, so I will defer that question(s) to someone else. Any NHRA-accepted carb, intake, block, heads, etc may be used.