Made by TCE, this extremely high quaility double roller timing set literally fixes the weak link in any 3100, 3400, or 3500 (LX9) engine.  Timing set features sprockets machined out of 4140 otherwise known as chromemoly.  It has multiple settings for timing advance (0, +3, +6, -3, and -6).  Please note this timing set does require modification to the crankshaft and timing cover for proper clearancing.