A concrete curb forming and extruding apparatus with wheel adjustment locks, and an adjustable slip form system shaping cementitious material into a continuous curb forced there through by an extruder which receives materials stored in a hopper with dasher. The extruder has a rotary trowel compacting member which continually forces material from the hopper into compressed concrete passing through an adjustable slip form to fill the same and form differing shaped continuous curbing underneath fences or against vertical surfaces or conventional curbing, depending upon the slip form setting.