| Engine S/N Base | Engine S/N Last |
|---|---|
| 46B6447 | - Up |
| Comment: Cylinder Head Replacement/Spacer Plated | |
| 47B470 | - Up |
| Comment: Cylinder Head Replacement/Spacer Plated Converted Engines | |
| 46B870 | -6446 |
| Comment: Cylinder Head Replacement/Spacer Plated Converted Engines |