68 SPECIFICATIONS Valve Guides Valve Springs Length Inlet/Exhaust 83.5 mm (3.287 inches) Inner diameter Inlet/Exhaust 8 mm (0.315 inch) Height above cylinder head spring surface Inlet/Exhaust 24.5 ± 0.2 mm (0.965 ± 0.008 inch) Inlet valve spring Length unloaded 73.8 mm (2.91 inches) Exhaust outer valve spring Length unloaded 73.8 mm (2.91 inches) Exhaust inner valve spring Length unloaded 70.5 mm (2.78 inches)