The Muffler,exhaust, cataloged under National Stock Number 2990-00-705-5076, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 2990-00-705-5076 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Status | ACTIVE |
| Inlet Flange Shape | ROUND SINGLE INLET |
| Operating Position | UNIVERSAL |
| Inlet Location | NONCENTRALLY LOCATED IN END SECTION OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Center to Center Distance Between Mounting Holes | 120 DEG APART ON 360 DEG BOLT CIRCLE SINGLE INLET |
| Outlet Inside Diameter | 4.000 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Projection Length | 1.750 INCHES NOMINAL SINGLE INLET IN |
| Outlet Outside Diameter | 4.312 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Connection Type | FLANGE SINGLE INLET |
| Body Shape | OVAL |
| Inlet Flange Mounting Provision and Quantity | 3 HOLES SINGLE INLET |
| Surface Treatment | PLASTIC POLYPROPYLENE |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 0.500 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | UNTHREADED FIRST OUTLET |
| Outlet Location | NONCENTRALLY LOCATED IN END SECTION OF BODY |
| 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 |
|---|---|
| 326431-1 | 3/9 Design control — primary reference U.S. Government activity |
NSN 2990-00-705-5076 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): 5998-01-079-1187. Verify interchangeability with system specifications before substitution.
Key specifications for 2990-00-705-5076: Inlet Flange Shape: ROUND SINGLE INLET; Operating Position: UNIVERSAL; Overall Height: 10.125 INCHES NOMINAL IN; Inlet Location: NONCENTRALLY LOCATED IN END SECTION OF BODY. 17 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.