E I 250 ENGINEPAASSEMBLY 4 I I l 0 829 PISTONIASSEMBLY with Pin l i I I l NOTE Individual piston assemblies are available for warranty purposes and for replacement of pistons damaged when makingrepairs to enginezassemblies When ordering such partsrit is necessary that you specify on your order the reason the partsare required and also that the following note appears on your order Do not ship unit package quantity NOTE See Dealer Price Schedule P A 26 for applicable prices I J r PISTON CHART I K STD 001 0 S 010 0 S 020 0 S 030 0 S 88 71 All Blazer 250 exc l L P Gas 3886048 3886049 v 3886051 E 89 72 All w L P Gas 250 3953798 5 R K l 72 All Blazer exc L P Gas 6270033 6270034 l 6270036 0 843 RING UNIT Piston Service Sets 1 V NOTE See Dealer Price Schedule P A 26 for applicable prices V r 4 Original Equipment Type complete set for oneengine per container STD K 020 O S 030 O S 040 O S l y 86 72 All Blazer 250 326400 38923880 328503 A 1 1 NOTE 1 These are Molybdenum premium rings NOTE 2 Only half of the components in this unit are required for 4 cyl models three quarters are required for 6 cyl models y 0 848 I CRANKSHAFT P r K NOTE 1 When used on A lZ it will be necessary to remove the pilot bearing 68 72 All Blazer 250 L X 3878840 1 Note 1 L 0 649 BEARING Crankshaft Clutch Pilot 8 g 88 72 All Blazer 250 3752487 1 bush type gz I D X 1 u 0 D x K 0 859 BALANCER KEY PULLEY Crankshaft I V NOTE 1 Used with pulleys and hubs having a shallow i deep keyway only All full depth slots take standard Woodruff key 10675 1 two short or 144542 one long in group 8 960 NOTE Crankshaft harmonic baIancer is also referredtoras torsional damper NOTE ln some cases double groove pulleys maybe used in place of single groove pulleys 68 72 All Blazer 250 A 3898590 1 w 2 groove pulley I 1 86 All w key long x ir wide E x high 3883208 A R KEY crankshaft pulley hub Note 1 88 All w key long x wid6 I I A x high I 3885092 1 KEY crankshaft pulley hub Note 1 68 All w Acc Air Cond 250 3790337 1 PULLEY stamped 3790337 1 groove 6 O D 3 holes 66 72 All Blazer 250 3883263 1 PULLEY stamped 3883263 1 groove V 6 I 0 D x thk 3 holes I 0 666 FLYWHEEL with Ring Gear K 1 s l 88 70 D D 250 exc KA T V A 86 Ser 30 250 exc D D K 88 70 Ser 10 20 Blazer w H D Clutch 4 Spd 250 exc D D I 87 70 Ser 30 250 exc A T D D I 71 72 AlI Blazer w H D Clutch 4 Spd 3998281 1 solid type 88 70 Ser 10 20 Blazer 250 exc D V V D 4 Spd A T H D Clutch 71 72 Ser 10 thru 30 Blazer exc A A T H D Clutch 4 Spd 3988390 1 solid type 88 70 All Blazer w P G 250 I I I 71 G 10 20 w P G lst design 3789821 1 spoke type 57 72 G 10 20 250 exc A T 368880 1 68 70 All w T H 400 250 340298 1 spoke type 89 70 All Blazer w T H 350 250 I 71 G 1 2 w P G 2nd design 71 72 All Blazer w A T 1 3991402 1 spoke type I I 0 669 BOLT Flywheel to Crankshaft t I I 4 68 72 All BIazer 250 exc A T 839758 8 20 x l i 88 72 All Blazer w A T 250 3727207 6 20 x 290M steel s GM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET 72TL21 l 0 629 0 689 f 0 30 t REV 5 79 I 4