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Pontiac MuscleCars - Pontiac Engines

      To determine what engine is installed, there are three things you can check. They will help you determine if you have a number matching engine or a transplanted one.
    1. Engine Production Date Code
    2. Engine Code
    3. Engine Casting Number

Pontiac V-8s
1. Engine Production Date Code
      All blocks were cast with a date production code. This code is on the distributor pad. This is a letter, followed by two or three digits. The letter signifies the month (A=January, etc.). The letter "L" stands for the month of December for all years, except 1966 (1967 model) when the letter "M" was used for December. The 2nd and 3rd (if used) digits represent the month of the year. The last digit designates the year of production (not necessarily the model year).
    Examples:
    A #9778840 block with a date code of F25 = June 2, 1965.
    A #9790071 block with a date code of L248 = December 24, 1968.


Pontiac V-8s
2. Engine Code
      The engine code is located on the front of the block, just in front of the #2 cylinder. The list below covers different models but not all are included.
Year Engine HPEngine Code (Automatic)Engine Code (Manual)
1964326 cid25092J92X,92W
1964326 cid28094J94X,94W
1964389 cid32579J78X,78W,789
1964389 cid34877J76X,76W,769
1965326 cid250ZNWP
1965326 cid285YPWR
1965389 cid335YSWT
1965389 cid360YRWS
1966326 cid250XF,YNWX,WP
1966326 cid285XG,YPWR
1966389 cid335YS,XEWT,WW
1966389 cid360YRWS,WV,XS
1967326 cid250YO,YN,XF,YJ,XIWP,WX,WC,WH
1967326 cid285YP,XG,YM,XOWR,XR,WK,WD
1967400 cid255XL,XMNONE
1967400 cid335YSWT,WW
1967400 cid360 HOYZWS,WV
1967400 cid360 RAXPXS,YR
1968350 cid265YN,YJWD,WC
1968350 cid320YP,YMWR,WK
1968400 cid265XM,YANONE
1968400 cid350YS,XHWT,XZ
1968400 cid360 HOYZWS
1968400 cid360 RAXPXS
1968400 cid360 RA IIXWWY
1969350 cid265XL,YJ,XR,YN,XB,YE,UY,XSWC,WP,WM,WU
1969350 cid330XT,XU,YPWR,WV
1969400 cid265XM,YZ,XX,YB,YFNONE
1969400 cid350YS,XHWT,WX
1969400 cid366 RA IIINONEWS,YZ
1969400 cid370 RA IVNONEWW,XP
1970350 cid255X7,YUW7,WU
1970400 cid265XX,YBNONE
1970400 cid330XZ,XVNONE
1970400 cid350XH,YSWX,WT
1970400 cid366 RA IIINONEWS,YZ
1970400 cid370 RA IVXPWW
1970455 cid360TC,YHWA
1971350 cid250XR,YU,YN,YPWR,WU,WN,WP
1971400 cid265XX,YXNONE
1971400 cid300YSWK,WT
1971455 cid325YCNONE
1971455 cid335 HOYEWL,WC
1972350 cid160,175YU,YV,YRWR
1972400 cid200ZV,ZXNONE
1972400 cid250YS,YT,ZSWK,WS
1972455 cid220YA,YC,Y4NONE
1972455 cid250YD,YKNONE
1972455 cid300 HOYB,YEWD,WM
1973350 cid150,175Y2,Y7,YR,YV,ZR,ZV,WA,WC,WD,WF,WL,WN,XZXR,WV,ZB,ZD
1973400 cid170,185YI,YP,YX,YZ,Y4,ZK,ZX,XH,XI,X3,X4NONE
1973400 cid200,230YN,YX,YT,Y3,ZN,ZS,XK,XN,XX,XZ,X5WK,WS,WP,YF,Y6,YG
1973455 cid215,250YA,YC,YD,YK,ZA,AC,XA,XE,XJ,XL,XY,XT,X7,XO,YENONE
1974350 cid155,170AA,YA,YB,YC,ZB,YN,YP,YS,ZAWA,WB
1974350 cid170,185,200YN,YP,YS,ZPWN,WP
1974400 cid175,190AH,YH,YJ,ZH,ZJ,AD,YF,YK,ZD,ZKNONE
1974400 cid200,225AD,YL,YM,ZS,AT,YT,YZ,ZTWT,WR,Y3
1974455 cid215,250AU,YR,YU,YW,YX,YY,ZU,ZW,ZX,A4,Y4,Y6,Y9,Z4,Z6NONE

3. Engine Casting Number
      Beginning in 1967 the block casting number changed location from the distributor pad to the rear of the block, just behind the #8 cylinder. The list below covers different models but not all are included.
Year Engine Casting Number
1964326 cid #9773153
1964 389 cid #9773155
1964 421 cid #9773157
1965 326 cid #9778840
1965 389 cid #9778789
1965 421 cid #9778791
1966 326 cid #9778840
1966 389 cid #9778789
1966 421 cid #9778791
1966 421 cid #9782611
1967 326 cid #9786339
1967 400 cid #9786133
1967 428 cid #9786135
1968 350 cid #9790079
1968 400 cid #9790071
1968 400 RA #9792506
1968 428 cid #9792968
1969 350 cid #9790079
1969 400 cid #9790071
1969 400 RA #9792506
1969 428 cid #9792968
1970 350 cid #9799916
1970 400 cid #9799914
1970 400 RA III #9799914
1970 400 RA IV #979991(5)
1970 455 cid #9799140
1971 350 cid #481990
1971 400 RA #481988
1971 455 cid HO #483677
1971 455 cid #485428
1972 350 cid #481990
1972 400 cid #481988
1972 455 cid #425428
1973 350 cid #488986
1973 400 cid #481988
1973 455 cid #485428
1973 455 cid SD #490132
1974 350 cid #488986
1974 400 cid #481988
1974 455 cid #485428
1974 455 cid SD #490132
1975 350 cid #488986
1975 400 cid #488986
1975 400 cid #500557
1975 455 cid #500813
1976 350 cid #488986
1976 400 cid #500557
1976 455 cid #500813


Pontiac GTO/GT-37 Illustrated Identification Guide!
Pontiac GTO/GT-37 Illustrated Identification Guide!


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