Distributor (1) Shaft end play ...197 to 198 mm (7.75 to 7.80 in) The distributor end play will be checked with the distributor in an inverted position from normal. Measure from the mounting surface to the face of the gear. Sensor Gap The Air gap (X) between the trigger wheel and the module is preset by General Motors. Therefore no adjustment can be made or is required. G643(E) Service Manual Chapter 4. Engine Electrical System 111