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.) Shock uses a shorter rod end than our 3840-1 and is 10.2" compressed and 14.1" extended to fit a 11.5"-12.5" ride height. Includes coil-over hardware. Suggested 7" or 8" tall spring sold separately.