COMP Cams Guide Plates GM LS1 5/16 Flatflat, 1 piece, non adjustableFor 5 16" diameter pushrods and 8mm Rocker StudsFit GM LS engines with "cathedral port" cylinder heads (Ex. LS1, LS6)Designed using stereo lithography Techniques for an accurate fitFeature exact Stud placement and rounded contact pointsNecessary for high lift spring pressure environments of performance enginesHardened and black oxide finished Catalog User 1 This Part Fits: Year Make Model Submodel 2001 2004 Avanti II Base