Mercury - Reverse Gear Assembly - Counter Rotation - for 5.44 Torpedo Lower Units Only - See Below for Applicable Engines - 8M0146668 175 HP 3.4L V6 - Serial number range 2B529482 and above 200 HP 3.4L V6 - Serial number range 2B529482 and above 200 HP 3.4L V6 SeaPro - Serial number range 2B529482 and above 225 HP 3.4L V6 - Serial number range 2B529482 and above 250 HP 3.4L V6 - Serial number range 2B529482 and above 250 HP 4.6L V8 Verado - Serial number range 2B529482 and above 250R HP 3.4L V6 Racing - Serial number range 1E080500 and above 300 HP 4.6L V8 Verado - Serial number range 2B529482 and above 300 HP 4.6L V8 Verado SeaPro - Serial number range 2B529482 and above 300R HP 4.6L V8 AMS Racing- Serial number range 1E081459 and above 300R HP 4.6L V8 Racing - Serial number range 1E080500 and above