Sierra 18-5290 Hi Performance Conversion Kit Sierra Hi Performance Conversion Kit fits most Mallory YL or YD 8 cylinder distributors w/ clockwise & counter clockwise rotation. Senses current levels in the coil and adjusts the dwell to maintain peak energy throughout RPM Range; Develops, on average, 4 times more available energy between 3000 and 5000 RPM's; Develops, on average, twice as much plug voltage as point-type systems; More stable timing; Use with 18-5472 "Flame Thrower II" Coil for optimum performance; Ignition energy sustains/coil life increased when peak current level is reached prior to spark; Resistance Ohms: 0.6 Use with: 18-5472 Hi-Performance Ignition Coil