14.5% on a 450 is about as easy as it can get , the primary gear and clutch basket are right out a 300 , no cutting , welding or grinding to build it , drops right in -----you need to take your right side cover off , remove both clutches and swop the parts , I would suggest a new set of clutches for the change clutch and soak them in oil prior to installing , not a fan of the heavy duty springs that come in the EBC clutch kits as it makes it harder to shift , I would use the stock springs