This Valve spring made by ITMS is a direct replacement in a BA, BF and FG & FGX XR6 turbo or F6. This spring will drop straight in using your original retainer and collets. Using the correct valve spring is very important as poor valve springs will effect engine power, idle quality and not to mention premature ware on valve components. This spring is designed to use with std cams and will cope with up to .500 lift.
Another thing to consider when the valve is floating (result of poor valve springs) the intake charge is contaminated with exhaust gasses, leading to detonation or engine knock. A std early model XR6 turbo valve spring has a seat pressure of around 35 lb and @ full lift 130 lb of pressure. Our spring has a seat pressure of 95 lb and @ 500 th lift it has 235 lb of pressure. Our High performance valve spring is good for 450 plus rwkws. 00018203