| Part Number | OEM # | Length | Inlet/Outlet | Sensor | Additional Info |
| BN-521B | 50" | shield crimps on, oval body, (up to 1996 models) | |||
| BN-521C | U98 | 55" | shield crimps on, round body, (1996+ models) |
| measurements required |
| overall length; shield bolts on or crimps on converter; round or oval body |
BN-817A (in front) bolted to BN-521C (in rear)