BN-558A/BN-558B
| A - 3 bolt dual inlet flange, 2 bolt outlet, 41" length |
| sensor in side neck where Y meets together, OEM# DA1 |
| B - 3 bolt dual inlet flange, 2 bolt outlet, 45" length |
| sensor in side neck where Y meets together, OEM# DA1 |
| BN-558 bolts behind BN-763A and BN-763B |