The reason is cost. Some people don't want to spend the extra money. The 2.4 with CH is $80 higher. If you want or need the extra power the CH Syncro-Spark comes from FPE with a 30deg hub. The reason Kurt at FPE sets the timing to 18deg for the fixed timing Ridge ignition is safety(kick back on starting). Options sometimes are nice, Cass. or CD player in your new car?