We designed this 4" stroke shock with valving specifically tuned for mono-shock swing arm dragsters. Recommended for 1,000-1,500 hp applications. (For higher hp see p/n 3240-1.) 4" stroke is 11" compressed and 14.92" extended to fit a 12.25-13.25" ride height. Includes coil-over hardware. Suggested 8" tall spring sold separately.