there was a thread only about a month ago where someone else had exactly the same issue and fixed it by fitting non Japanese branded valve springs, really it's up to you, you can listen to people who have real world experience with their own cars, or you can listen to brand fan boys who's experience is something they once read that someone posted about their neighbors cousins sisters boyfriends friends carAt the end of the day it's your money and your car and what you do with them is your choice, but it's not always the poor man that pays twice, some times the ignorant man does as well