A use to do a lot of dirt drag racing. It was 4x4s on a 300ft dirt track. Otherwise it was just like racing on asfalt. We did bracket racing and class racing. Many guys would have 2 engines. A big bracket motor and a small class motor. The classes were based on a weight per cubic inch ratio so the smaller engines had the advantage. Many guys ran 283, 302 and 327 chevies. The ford guys ran 289 and 302 fords. Some were more exotic "destrokers" like 351 Clevelands destroked to just over 300. Some Chevies were destrokers 350s and 400s with 283 and 302 cranks. It was and still is rare to see a big engine in a class being competitive.

In a weight/cubic inch race the smaller engines don't really make more power than big engines. The advantage is in the fact that they can carry less weight.
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