Custom solid lifter camshafts. Designed for modified engines with larger turbos. Bigger cc injectors, CNC ported cylinder head, MoTeC or equivalent ECU necessary for big gains. Requires BC spring & retainer kit. ECU tune, cylinder head work, intake/exhaust are mandatory for optimal gains. Complete BC CNC cylinder head packages available. Now includes crank locking tool (#529036272) to insure proper installation.