Service Replacement (SR) blocks do not always have a code stamped on the front of the engine. They do, however, usually have a casting number. This casting number is usually on the RH side of the rear portion of the block - where the transmission bolts up.
Here they are:
| 400 | |
|---|---|
| Year | Numbers |
| 1967 | 9786133 |
| 1968 | 9790071 |
| 1968 RAM AIR | 9792506 |
| 1969 | 9790071 |
| 1969 RAM AIR IV | 9792506 |
| 1970 | 9799914 |
| 1970 RAM AIR IV | 9799915 |
| 1970-74 | 481988 |
| 1975 | 488986 (early) 500557 (late) |
| 1976 | 500577 |
| 1977-79 | 568577 |
| 1978-79 (T/A 6.6) | 481988 xx |
| 428 | |
| Year | Numbers |
| 1967 | 9786135 |
| 1968-69 | 9792968 |
| 455 | |
| Year | Numbers |
| 1970 | 9799140 |
| 1971 | 483677 (early) 485428 (late) |
| 1972-74 | 485428 |
| 1973-74 (SD) | 490132 |
| 1975-76 | 500813 |
