I 4 250 ENGINE ASSEMBLY 4 4 up 0 429 4 BALL NUT STUD Valve Push Rod Adjusting Con t 1 y 66 72 All Blazer 250 Q 3814692 16 STUD valve rocker arm ball 003 0 S 4 4 A 24 x 2 I 2 grooves on shank light blue paint 66 72 All Blazer 250 3815892 16 STUD valve rocker arm ball 013 O S V 24 x 2 J 1 groove on shank light I 1 blue paint a 0 439 COVER Valve Push Rod 4 66 72 All Blazer 250 3788496 2 4 x 12 4 4 0 443 GASKET Valve Push Rod Cover 4 68 72 All Blazer 250 3920938 2 R 4 0 446 BOLT VaIve Push Rod Cover 66 72 All Blazer 250 I 3814350 A R w lockwasher and seal 18 x 60 459 TAPPET Valve or Lifter f 4 4 V 4 66 72 All Blazer 250 5232450 A R I hydraulic type 4 Q 0 519 CAMSHAFT I 4 4 I NOTE Engine Camshaft Break in Oil Group 1 850 should be used when installing new camshafts 66 11 All Blazer 250 3864497 1 Ident No 3865896 or 3850958 A 72 AII Blazer 250 6262809 1 i 0 533 BEARING UNIT Camshaft Thrust 4 66 72 All Blazer 250 3790531 1 BEARING UNIT w spacing ring 1 0 0 V x 1 1 0 0 539 BEARING Camshaft All Locations 1 thru 5 4 4 66 69 All Blazer 250 I front inter No 2 rear inter No 3 70 72 All Blazer 250 I 3750684 A R 4 all locations No 1 2 3 4 66 69 All Blazer 250 3750882 A R front No 1 rear No 4 4 0 543 BEARING Camshaft Front Intermediate See Group 0 539 for Model Application 44 0 546 BEARING Camshaft Center and Rear Intermediate See Group 0 539 for I I Model Application 0 549 BEARING Camshaft Rear See Group 0 539 for Model Application 0 553 PLUG Camshaft Bearinglwlole Cup Type In Cylinder Block 68 70 AII Blazer 250 3704158 441 4 2 dia Q 71 72 All Blazer 250 3994255 1 rear steel 2 dia x thk 4 0 603 ROD ASSEMBLY Connecting Less Dipper 66 72 All Blazer 250 Q 1 39771 10A R I cap forged 3788437 4 0 616 BEARING UNIT Connecting Rod4 1 Upper and 1 Lower 4 4 I Refer to chart for Model Application 4 4 NOTE See Dealer Price Schedule P A 26 for applicable prices V 4 CONNECTING ROD BEARING UNIT CHART MODEL USAGE STD 001 U S 002 U S 010 U S 020 U S 66 72 AII Blazer 250 347118 344 7119 I 3715046 3715048 3715047 0 623 BOLT Connecting Rod Bearing Cap 66 72 All Blazer 250 460405 A R 4 4 0 626 NUT Connecting Rod Bearing Cap Bolt a NOTE 1 Also used with bolts not requiring cotter pins 66 72 All Blazer 250 3815280 16 24 type EA phosphate coated and soaped 66 72 All Blazer 250 3866766 A R 24 x thick hex nut both ends V flat Note 1 I GM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET 72TL 4 REV 5 79 0 za i 0 429 0 626