I have a set of main caps from a 426 Hemi that I suspect are from either a '64-'65 race Hemi or the '68 Barracuda/Dart cars. On the outer cross bolt bosses, caps #2, #3 and #4 are drilled and tapped vertically....maybe for a windage tray? I know the '66 and later Street Hemi main caps didn't have this attachment method. Any ideas on what these are? Thanks!