Skyjacker Softride Series Coil Spring - 2.500 in ID - Dual Rate - Black - 2-1/2 in Lift - Rear - Jeep Wrangler 1997-2006 (Pair) Engine Fastener Kits Inside dimensions 12-3/4 Inch x EBCRK7435

Skyjacker Softride Series Coil Spring 2.500 in ID Dual Rate Black 2 1 2 in Lift Rear Jeep Wrangler 1997 2006 (Pair) Engine Fastener Kits Inside dimensions 12 3 4 Inch x EBCRK7435 Inside dimensions 12 3 4 Inch x 7 1 4 Inch x 10 Inch tall Features:Pre installed Bronze Gear for aftermarket billet roller camshaftsGear machined from AMPCO 45 aluminum bronze containing 5% NickelCNC machined billet 6061 T6 aluminum housingMaintenance free magnetic pickup and precision reluctor create stable trigger signals throughout the rpm rangeEasy to adjust mechanical advance with supplied springs and stop bushingsNylon pads ensure smooth operation of the advance weightsAdvance weight pins are staked and TIG welded to the plateAdvance plate and weights are fine blanked from chrome moly steel and QPQ coated for friction reductionPolished steel shaft is QPQ coated and guided by a sealed ball bearingMechanical advance assembly can be locked out for crank trigger systemsSupplied with Cap A Dapt and rotor (accepts MSD socket style caps)Must be used with an MSD Ignition Control Maximum Articulation Matched To OEM Ride