The Muffler,exhaust, cataloged under National Stock Number 2990-00-407-4968, 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17 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-407-4968 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Status | ACTIVE |
| Operating Position | UNIVERSAL |
| Inlet Location | CENTRALLY LOCATED ON END OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Overall Diameter | 1.750 INCHES NOMINAL IN |
| Inlet Thread Location | EXTERNAL SINGLE INLET |
| Inlet Projection Length | 1.250 INCHES NOMINAL SINGLE INLET IN |
| Muffler Design | STRAIGHT THROUGH |
| Inlet Connection Type | THREADED SINGLE INLET |
| Thread Direction | RIGHT-HAND SINGLE INLET |
| Body Shape | ROUND |
| Nonconnection Outlet Location | CENTRALLY LOCATED ON END OF @BODY OPPOSIT INLET |
| Nonconnection Outlet Type and Quantity | 1 ROUND HOLE |
| Inlet Thread Size | 3/8-18 SINGLE INLET |
| Nonconnection Outlet Size | 0.625 IN. DIA IN |
| Inlet Thread Series Designator | NPT SINGLE INLET |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| 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 |
|---|---|
| M375 | 3/2 Design control — primary reference U.S. Government activity |
NSN 2990-00-407-4968 is a Muffler,exhaust, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4330-01-240-2838, 5950-01-330-6489. Verify interchangeability with system specifications before substitution.
Key specifications for 2990-00-407-4968: Operating Position: UNIVERSAL; Inlet Location: CENTRALLY LOCATED ON END OF BODY; Coolant Type: AIR; Design Type: DRY. 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.