CHEVY 823 SQUARE PORT. VALVE SEAT CUTTER KIT. 1x 30 DEG INTAKE TOP CUT. 1x 45 DEG INTAKE BASE CUT. 1x 60 DEG INTAKE BOTTOM CUT. 1x 30 DEG EXHAUST TOP CUT. 1x 45 DEG EXHAUST BASE CUT. 1x 60 DEG EXHAUST BOTTOM CUT. 3x VALVE GUIDE STEMS LONGER HEAVY DUTY. 3x VALVE GUIDE REAMER SELF PILOTED. Track Page Views With.