Decoding Engine Stampings and Casting Numbers
Decoding
the Stampings on Engine Pads:
| A | .020 oversize cylinder bores |
| Diamond | Oversize tappets |
| E | Cast Crankshaft |
| HP | High Performance |
| L or LC | Low compression |
| Maltese Cross | .001" undersize main bearing journals |
| Maltese Cross & an X | .010" undersized crankshaft rod journals |
| O.S. | .005" oversize valve stems |
| P | Premium Fuel |
| R | Regular Fuel |
| RX or MX | All main and rod journals .010" undersized |
| S | Special engine |
| WT or TW | Water Test |
| X | .010" undersize crankshaft |
Decoding
the Year Codes for B & RB Engines:
(Stamped on engine pad)
| A | 1965 |
| B | 1966 |
| C | 1967 |
| D | 1968 |
| E | 1969 |
| F | 1970 |
| G | 1971 |
| H | 1972 |
| J | 1973 |
| P | 1960 |
| R | 1961 |
| S | 1962 |
| T | 1963 |
| V | 1964 |
| 4T | 1974 |
| 5T | 1975 |
| 6T | 1976 |
| 7T | 1977 |
| 8T | 1978 |
Decoding B / RB Engine Block Casting Numbers:
| Casting # | Body | B or RB | Year | Stock Cubes |
| 1944929 | Chrysler/Dodge/Plymouth | B | 58 | 350 |
| 1737629 | Chrysler/Dodge/Plymouth | B | 61-64 | 361 |
| 2205712 | Chrysler/Dodge/Plymouth | B | 58-66 | 361 |
| 1851729 | Chrysler/Dodge/Plymouth | B | 59-64 | 383 |
| 2120329 | Chrysler/Dodge/Plymouth | B | 59-64 | 383 |
| 2468130 | Chrysler/Dodge/Plymouth | B | 59-71 | 383 |
| 3698630 | Chrysler/Dodge/Plymouth | B | 73-78 | 400 |
| 3614230 | Best
B (400) Block (Heavy Main Webs) |
B | 71-72 | 400 |
| 1852029 | High Performance & Truck | RB | 62 | 413 |
| 2120529 | Chrysler/Dodge/Plymouth | RB | 59-65 | 413 |
| 2205697 | Chrysler/Dodge/Plymouth | RB | 59-65 | 413 |
| 2205697 | Chrysler/Dodge/Plymouth | RB | 64 | 426 |
| 2406730 | Max Wedge | RB | 63-65 | 426 |
| 2532230 | Max Wedge | RB | 64-66 | 426 |
| 2536430 | Chrysler/Dodge/Plymouth | RB | 66-72 | 440 |
| 3698330 | Chrysler/Dodge/Plymouth | RB | 73-78 | 440 |
| 4006530 | Chrysler/Dodge/Plymouth | B | 76-78 | 400 |
| 4006630 | Chrysler/Dodge/Plymouth | RB | 78 | 440 |
Decoding Big Block Cylinder Head Part Numbers:
(* = Most Popular)
| Casting # | Part # | Year | Engine | Chamber Type |
Intake Dia. |
Exhaust Dia. |
| 1737637 | 2128533 | 58-59 | 361 | Closed | 1.94 | 1.60 |
| 1944705 | 2128533 | 58-59 | 361 | Closed | 1.94 | 1.60 |
| 1737637 | 2448752 | 60 | 361/383 | Closed | 1.94 | 1.60 |
| 2206924 | 2128589 | 61-62 | 361/383/413 | Closed | 2.08 | 1.60 |
| 2206324 | 2128589 | 61-62 | 361/383/413 | Closed | 2.08 | 1.60 |
| 2402286 | 2402358 | 62 | 413 Max Wedge | Closed | 2.08 | 1.88 |
| 2463209 | 2406754 | 63 | 426 Max Wedge | Closed | 2.08 | 1.88 |
| 2463200 | 2448752 | 63 | 361/383/413 | Closed | 2.08 | 1.60 |
| 2406518 | 2406736 | 64 | 426 Max Wedge | Closed | 2.08 | 1.88 |
| 2406516 | 2406732 | 64-67 | 361/383 | Closed | 2.08 | 1.60 |
| 2406158 | 2806019 | 67 | 440 | Closed | 2.08 | 1.60 |
| *2780915 | 2800762 | 67 | 440 HP | Closed | 2.08 | 1.74 |
| *2843906 | 2843904 | 68-70 | 383/440 | Open | 2.08 | 1.74 |
| 2951250 | 2843904 | 68 | 440 | Open | 2.08 | 1.74 |
| 3462346 | 3462344 | 71-72 | 383/400/440 | Open | 2.08 | 1.74 |
| 3462346 | 3671640 | 73 | 400/440 | Open | 2.08 | 1.74 |
| 3751213 | 3751218 | 73 | 400/440 (Motor Home) |
Open | 2.08 | 1.74 |
| 3769902 | 3769910 | 74 | 400/440 | Open | 2.08 | 1.74 |
| 3769975 | 3769954 | 75 | 400/440 | Open | 2.08 | 1.74 |
| 4006452 | 3769954 | 76-78 | 400/440 | Open | 2.08 | 1.74 |