ENGINE INSTALLATION INSTRUCTIONS PART NO 3930911 CONT GENERAL INFORMATION CONT 5 Models with optional equipment require transfer or replacement of engine parts special to such options 6 When using on Powerglide I urbo Hydramatic or Powermatic vehicles remove clutch pilot bearing 7 If any part number listed above is not shown in the current parts catalog check history section of catalog for replacing parts 8 The intake manifold of this engine is equipped with a vacuum source located on the center branch for the crankcase ventilation system If desired this vacuum source can be used on past models by re moving the dust seal and installing connector part number 3859374 transferring the hose and clamp from the outboard fitting to the connector IMPORTANT lf the above source of vacuum is not used plug the opening with a 3 8 cup plug Part No 838323 If converting to use the added source of vacuum plug previously used opening with pipe plug Part No 9420756 lf above is used on vehicles equipped with vacuum power brakes seal previously used source of ventilator vacuum by pinching tube to prevent leakage it asf i j 1970 CHEVROLET MOTOR DIVISION GENERAL MOTORS CORPORATION P A 315 58