Most high performance engines today require the use of larger-than-stock diameter valve springs. This 1.580" Spring Seat Cutter from COMP Cams will allow the engine builder to machine the cylinder head to the proper size for your spring. Each cutter requires the use of an arbor/pilot, which are available in three different sizes.
This valve seat cutter allows you to enlarge the cylinder head spring pocket to 1.580" outer diameter while reducing the outer diameter of the valve guide to .560".
Cuts spring seat to 1.580" O.D.; Cuts guide to .560"; Other seat cutters available in many sizes from 1.350" to 1.810" O.D.