Pontiac 265-455 Technical Page

 

PONTIAC ENGINE TECHNICAL INFORMATION
 

True Pontiac engines were made by the Pontiac Motor Division.  Pontiac engines were last produced and used in 1981.  Pontiac engines were available in many different displacements, ranging from 265 CID to 455 CID.  Components are interchangeable from each displacement, other than 265 & 301, which have manu components that are only compatible with themselves.  HO and Super Duty engines were the most desirable.  SD engines have 4-bolt main blocks.  There were also numerous head castings.

Pontiac engines ceased production on April 1, 1981

 

 

BASIC ENGINE INFORMATION
 Pontiac block diagram
 Cylinder 1 : Front Left

Firing Order : 1-8-3-4-5-7-2 (Counter Clockwise)
67-76 uses 3-holt oil pan front gasket
77-81 uses 5-hole oil pan front gasket

67-75 uses 2.75" crankshaft register
76-79 used 2.5" crankshaft register
73-74 SD uses a 2 9/16" crankshaft register

67-74 uses rubber mount on block
75-81 uses steel mount on block
Pontiac engines have the same firing order as a small block Chevrolet engine (1-8-4-3-6-5-7-2), but the distributor rotates counterclockwise whereas a SBC rotates clockwise.  This is the most common mistake when replacing a distributor.  77-81 265/301 engine blocks differ vs 79 and older 350/400/455 blocks.  Some people call the 77-81 265/301 "baby blocks".  The 265/301 engines only have 4 intake ports (vs 8) and the runners are shared between 2 cylinders.

 

 

 

PONTIAC BLOCK CASTING #'S
CASTING # DATE CID MAINS NOTE
481708 1970 400 4 Ram Air V
481988 1971-74 400 2  
481990 1971-72 350 2  
483677 1971-72 455 2  
483677 1971-72 455 2 or 4 HO
485212 1972 366 4  
485428 1971-74 455 2 or 4  
487638 1972 455 2  
488986 1975 400 2 Early Block
488986 1973-76 350 2  
490132 1973-74 455 4 SD
493482 1973 455 2  
500557 1975 400 2 Late Block
500810 1975 350 2 Late Block
500813 1975-76 455 2  
518037 1955 287 2  
521560 1956 316 2  
523293 1957 347 2  
525934 1977 301 2  
528456 1958 370 2  
532000 1959 389 2  
536387 1960 389 2 or 4  4 bolt SD
538181 1961-62 389/421 4 421 SD
542426 1961 389   SD
543680 1963 389 2  
544988 1963 421 2 SD Also
545887 1969 400 4 Ram Air V
546313 1969 303 4 Ram Air V (Short Deck)
548211 1963 326 2  
548913 1962 421 4 SD (Late Block)
568557 1977-79 400 2  
9773153 1964 326 2  
9773155 1964 389 2  
9773156 1964 326 2  
9773157 1964 421 2  
9773383 1964 389 2  
9773384 1964 421 2  
9778789 1965-66 389 2  
9778791 1965-66 421 2  
9778840 1965-66 326 2  
9782611 1966 421 2  
9786133 1967 400 2 or 4  
9786135 1967 428 4  
9786339 1967 326 2  
9787840 1967 326 2  
9790071 1968-69 400 2 or 4  
9790079 1968-69 350 2  
9792250 1968 400 2  
9792506 1968 400 4 Ram Air
9792506 1969 400 4 Ram Air IV
9792968 1969 400 4 Ram Air V
9792968 1968-69 428 2 or 4  
9799140 1970 455 2  
9799914 1970 400 2 or 4  4 bolt Ram Air III
9799915 1970 400 4 Ram Air IV
9799916 1970 350 2  

 

 

Pontiac 6X cylinder head    PONTIAC CYLINDER HEAD INFORMATION

CASTING # YEAR CID VALVE SIZE CC NOTES
518024 55 287 1.78/1.50    
522010 56 316 1.78/1.50    
523298 57 347 1.78/1.50    
524852 57 347 1.78/1.50   Fuel Injection
528511 58 347/370 1.78/1.50    
531395 59 389 1.78 or 1.88/1.50 or 1.60    
535461 60 389 1.92/1.60 68 Super Duty
536109 60 389 1.88/1.60    
538177 61-62 389/421 1.88/1.60    
540306 61-62 389/421 1.92/1.66 68 Super Duty
544127 61-62 421 2.02/1.76 68 Super Duty
9771980 62-63 421 2.02/1.76 68 Super Duty
543797 63 326/389/421 1.88/1.60    
544127 63 421 2.02/1.76 68 Super Duty
548332 63 326 1.92/1.66 68  
9770716 63 421 1.92/1.66 68 HO
9772652 63 326 1.92/1.66 68  
543796 63-64 389 1.88/1.60    
9770716 64 389/421 1.92/1.66 68 389 GTO
9773345 64 326/389/421 1.92/1.66 68  
9773395 64 326 1.92/1.66 68  
22 65 326 1.92/1.66 68  
62 65 326 1.92/1.66 68  
75 65 389 1.92/1.66 68  
76 65 389/421 1.92/1.66 68 389 GTO
77 65 389/421 1.92/1.66 68 421 HO
91 66 389 1.92/1.66 68  
92 66 389/421 1.92/1.66 70 389 GTO
93 66 389/421 1.92/1.66 68 421 HO
94 66 326 1.92/1.66 68  
95 66 326 1.92/1.66 68  
97 67 400 2.11/1.77 72 late Ram Air
61 67 400 2.11/1.77 72  
140 67 326 2.11/1.77 72  
141 67 326 2.11/1.77 72  
142 67 400 2.11/1.77 72  
143 67 400 2.11/1.77 72  
187 67 400 2.11/1.77 72  
670 67 400/428 2.11/1.77 72 400 Ram Air
997 67 400 2.11/1.77 72 Ram Air
671 67 400/428 2:11/1.77 72  
14 68 400 2.11/1.77 72  
15 68 400 2.11/1.77 72  
16 68 400/428 2.11/1.77 72 400 HO
17 68 350 2.11/1.77    
18 68 350 2.11/1.77    
31 68 400 2.11/1.77 72 Ram Air
37 68 400 2.11/1.77 72 Ram Air
62 68 400/428 2.11/1.77 72  
96 68 400 2.11/1.77 71 Ram Air II
214 68 400 2.11/1.77 72  
215 68 400 2.11/1.77 72  
216 68 400/428 2.11/1.77 72  
16 69 400/428 2.11/1.77 72 400 Ram Air III
44 69 400 2.19/1.66   Ram Air V
45 69 400 2.11/1.77    
46 69 400 2.11/1.77    
47 69 350 2.11/1.77    
48 69 350/400 2.11/1.77 72 400 Ram Air III
62 69 400/428 2.11/1.77 72 400 Ram Air III
722 69 400 2,11/1.77 71 Ram Air IV
184 69 303 2.19/1.62   Ram Air V
11 70 350/400 2.11/1.77    
12 70 400 2.11/1.77 72 Ram Air III
13 70 400 2.11/1.77 72 AT Ram Air III
15 70 455 2.11/1.77 72  
16 70 400 2.11/1.77   Press-in studs
47 70 350/400 2.11/1.77    
64 70 455 2.11/1.77 87 HO
614 70 400 2,11/1,77 71 Ram Air IV
66 71 455 2.11/1.77 114 AT
94 71 350 2.11/1.77 96  
96 71 400 2.11/1.77 96 GTO
98 71 455 2.11/1.77 111  
99 71 400 2.11/1.77 96  
191 71 455 2.11/1.77 111 HO
197 71 455 2.11/1.77 111 HO
7F6 72 455 2.11/1.77 111 HO
7H1 72 350 2.11/1.77 96  
7J2 72 400 2.11/1.77 96  
7K3 72 400 2.11/1.77 96  
7L4 72 455 2.11/1.77 96  
7M5 72 455 2.11/1.77 111  
16 73 455 2.11/1.77 111 Super Duty, screw in studs
46 73 350/400 2.11/1.66 98  
4C 73 350/400 2.11/1.66 98  
4X 73-74 400/455 2.11/1.66 98  
16 73-74 455 2.11/1.77 111 Super Duty , screw in studs
46 74 350/400 2.11/1.66 98  
4C 74 350/400 2.11/1.66 98  
51 75 455 2.11/1.66 101  
5C 75 350/400 2.11/1.66 101  
6H 75-76 455 2.11/1.66 124 HO
6S 75 455 2.11/1.66 124 HO
6S 76 350/400 2.11/1.66 124  
6X 76-78 350/400 2.11/1.66 101  
01 77-81 301 1.72/1.50    
6S 77 350 2.11/1.66 124  
6X 79 400 2.11/1.66 101  
65 80-81 265 1.72/1.50