Questions on tuning machines

I have a mim FenderP four string. And i'm slowly starting to modify it. no special reason to just that i want to. so my first upgrade were to seymour duncan pickups. and as i hoped it made quite a difference in over all sound of the bass. so now i'm thinking about upgrading to the tuning machines to the ones that come on the american made bass. now the ones that came with the mim there is nothing wrong with them as far as i can tell. so this is my first fender bass so i nothing to compare it to. so on to the point would it just be a waste of time and money to upgrade to the american tuning machines. this may sound silly to most but looking for some good advice. to make an above average bass even better. thanks for the help.