Clearance.... You mean gap?
If so, oem recommended gap is .054" (.052 - .056). I like to set mine a little closer though, at about .046" - .048".
Not sure on the cam gears question, but you should definitely plan on upgrading the valve springs. As far a tuning, an actual dyno tune is best but you can get away with an email tune. And if you really want to go crazy and do things right, a set of 24# injectors (not mandatory, but the slight upgrade will keep from getting to close to the max duty cycle of the stock 21#'ers).
If so, oem recommended gap is .054" (.052 - .056). I like to set mine a little closer though, at about .046" - .048".
Not sure on the cam gears question, but you should definitely plan on upgrading the valve springs. As far a tuning, an actual dyno tune is best but you can get away with an email tune. And if you really want to go crazy and do things right, a set of 24# injectors (not mandatory, but the slight upgrade will keep from getting to close to the max duty cycle of the stock 21#'ers).
