I have 327 factory gears in it . Car has 115k miles ( not sure if AOD was ever rebuilt , but it shifts good and no problems ) engine runs good also . I am considering having 410 Motorsport gears put in ( I know a mustang guy who is said to be very good with gear swaps ) question I have is will it stress the trans or engine too much ? I heard the 410 gears wake up these cars and increase fun factor ( it’s just a daily driver cruiser - not interested in racing )