I'm currently stripping the engine but need advice. I'm looking to change a cam but can't remember with what BD14 etc?. I'm looking for 400 420. Also what 1 do you change exhaust or inlet it has bd10s already. Other question its probably a silly 1 but when I'm changing the valve springs do I change all 16 or just the 1s with the BD14 or BD16 cam?