396 ENGlNE ASSEMBLY 0 659 BALANCER PULLEY Crankshaft C0n t 66 67 Pass El Camino 5 w C A C 396 exc Sp H Per T H 66 67 Pass w 62 amp C A C w T H 396 68 Pass Chevelle Camaro w C A C 396 1st design exc T H 3874414 1 14 80 PULLEY 2 grooves 72 S4 O D 65 66 Pass w 62 amp 396 exc Sp H Per Air Cond 66 EI Camino w A R 62 amp 396 exc Sp H Per 66 S S w A I R 62 amp 396 exc Sp H Per Air Cond 66 67 Pass w A l R 396 exc Sp H Per Air Cond 67 El Camino S S w A R 396 exc Air Cond Sp H Per 68 Chevy w H Per 396 68 Chevelle 396 exc Sp H Per C A C A T 68 Camaro 396 exc H Per Sp H Per C A C 68 Pass 396 exc C A C A T Sp H Per 3874418 1 13 60 PULLEY front 2 grooves 67 El Camino S S w T H 396 3876872 1 14 00 PULLEY 1 groove 67 Camaro w A l R 396 exc Sp H Per P S 67 Camaro w Sp H Per 396 67 Pass Chevelle A I R w Sp H Per 396 exc P S 3863108 1 48 75 PULLEY 2 grooves cast 68 All w P S 396 exc Sp H Per 3925525 1 12 90 PULLEY front 1 groove 69 70 All w Sp H Per 396 3955291 1 15 20 PULLEY 2 groove 69 70 Chevelle Camaro w Air Cond 396 69 Pass w Air Cond 396 exc A T 70 Pass Nova w Acc Air Cond 396 3937787 1 21 35 PULLEY 3 groove Note 1 69 Chevelle 396 exc C A C 3956666 1 15 20 PULLEY 2 groove 69 70 Chevy w H Per 396 exc P S 69 Camaro 396 exc C A C P S H Per Sp H Per 69 Chevelle Pass 396 exc C A C P S Sp H Per 70 Pass Chevelle Camaro 396 exc C A C P S Sp H Per 69 Chevelle w P S 396 exc C A C Sp H Per 69 Chevy Camaro w P S 396 exc Sp H Per 69 Pass w P S 396 exc C A C 70 Nova w P S H Per 396 70 Camaro Chevelle w P S 396 exc Sp H Per C A C 3955290 1 15 20 PULLEY 2 groove 69 Pass w Air Cond 396 70 Pass Nova Chevelle w Acc Air Cond 396 3972180 1 26 50 PULLEY 3 groove stamped 3972180 0 662 KEY WASHER Harmonic Balancer and Crankshaft Pulley NOTE 1 Used with pulleys and hubs having a sha ow is deep keyway only All full depth S slots take standard Woodruff Key 106751 two short or 144542 one long in Group 8 960 65 66 All w key 4 long x 6 wide x high 3883206 A R 31 crankshaft pulley hub Note 1 65 66 All w key 13 H long x 6 wide x gz high 3885092 1 28 KEY crankshaft pulley hub Note 1 65 70 All 396 3864814 1 1 05 WASHER balancer 0 666 FLYWHEEL Engine Crankshaft NOTE 1 On some application 3991401 and 3937736 are used optionally in production These parts can be identified by their bolt hole mounting patterns 3991401 contains a single bolt hole mounting pattern 1 1 z in dia 3937736 contains two staggered bolt hole mounting patterns The inner pattern 10 N in dia the outer 1 1 Z in dia NOTE 2 Used with dual plate clutch GM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET 11 REV 4 81 0 87 0 659 0 666