The Muffler,exhaust, cataloged under National Stock Number 2990-00-459-7257, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-459-7257 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Status | ACTIVE |
| Operating Position | HORIZONTAL |
| Inlet Outside Diameter | 2.250 INCHES NOMINAL SINGLE INLET IN |
| Inlet Location | LOCATED IN CENTER OF END SECTION |
| Coolant Type | AIR |
| Overall Diameter | 2.750 INCHES NOMINAL IN |
| Inlet Projection Length | 2.000 INCHES NOMINAL SINGLE INLET IN |
| Muffler Design | STRAIGHT THROUGH |
| Outlet Outside Diameter | 2.000 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Connection Type | UNTHREADED SINGLE INLET |
| Body Shape | ROUND |
| Inlet Integral Manifold Exhaust Pipe Length | 33.190 INCHES NOMINAL SINGLE INLET IN |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 2.000 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | UNTHREADED FIRST OUTLET |
| Outlet Location | LOCATED IN CENTER OF END SECTION |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 2573J | 5/9 Secondary reference U.S. Government activity |
| MU1036X | 5/9 Secondary reference Mahle Aftermarket Inc. Dba Ae Clevite Inc |
| 2856361 | 3/2 Design control — primary reference U.S. Government activity |
| 2003 | 5/9 Secondary reference Harvard Industries |
| MU1035X | 5/9 Secondary reference Mahle Aftermarket Inc. Dba Ae Clevite Inc |
NSN 2990-00-459-7257 is a Muffler,exhaust, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 1020-00-491-8594. Verify interchangeability with system specifications before substitution.
Key specifications for 2990-00-459-7257: Operating Position: HORIZONTAL; Inlet Outside Diameter: 2.250 INCHES NOMINAL SINGLE INLET IN; Inlet Location: LOCATED IN CENTER OF END SECTION; Coolant Type: AIR. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.