I have a set of BC springs(just single springs) and a set of ferrea springs(dual). I am going to be using 1mm oversize and 264 BC cams. I was wondering what everyones thoughts are on which ones I should use. I dont plan on seeing anything over 600hp and dont plan on revving anything over 8k. So basically is the dual springs overkill or more of a safety net? I have also heard some things about dual springs causing issues with the valve guides, any thoughts?