Speedway cars require a broad torque and power curve that comes on quick from 3500 rpm through to 6500rpm. A speedway engine needs to pull hard from 3500rpm to be able to be held on the boil in turns and accelerate hard and fast out of them.
The cams list here will provide that sort of power band, but they are race cams and they do require alot of finesse in engine tuning and selction of other combination of parts, compression, ignition timing, carbs, gears and diff ratios to make them work.