PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

FD78Muffler,exhaust

Maremont Corp · NSN 2990-00-846-0732 · FSC 2990 · No Item Name Available
Verified by PartsTable
NSN 2990-00-846-0732 — this item is cataloged by the U.S. Government under National Stock Number 2990-00-846-0732. Primary manufacturer part number: FD78.
Features
  • Muffler,exhaust — FSC 2990
  • Overall Diameter: 5.250 INCHES NOMINAL IN
  • Operating Position: HORIZONTAL
  • Inlet Outside Diameter: 1.875 INCHES NOMINAL SINGLE INLET IN
  • Inlet Location: OFFSET FROM CENTER IN BOTTOM
  • Surface Treatment: ALUMINUM
  • Inlet Connection Type: UNTHREADED SINGLE INLET
  • Coolant Type: AIR
Applications
  • Applications requiring Steel Location Not Otherwise Specified construction
General Description

The Muffler,exhaust, cataloged under National Stock Number 2990-00-846-0732, is classified within Federal Supply Class 2990 (No Item Name Available) of the Engine Accessories group. The primary manufacturer of record is Maremont Corp. Government technical data includes 18 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 13 commercial cross-references from 10 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN2990-00-846-0732
Primary Part NumberFD78
Item NameMuffler,exhaust
FSC / FSG2990 / 29 — No Item Name Available
ManufacturerMaremont Corp
StatusCANCELLED
Overall Diameter5.250 INCHES NOMINAL IN
Operating PositionHORIZONTAL
Inlet Outside Diameter1.875 INCHES NOMINAL SINGLE INLET IN
Inlet LocationOFFSET FROM CENTER IN BOTTOM
Surface TreatmentALUMINUM
Inlet Connection TypeUNTHREADED SINGLE INLET
Coolant TypeAIR
Outlet Projection Length1.875 INCHES NOMINAL FIRST OUTLET IN
Inlet Projection Length1.875 INCHES NOMINAL SINGLE INLET IN
Inlet Inside Diameter1.750 INCHES NOMINAL SINGLE INLET IN
Outlet LocationOFFSET FROM CENTER IN TOP
Body ShapeROUND
Outlet Inside Diameter1.375 INCHES NOMINAL FIRST OUTLET IN
Design TypeDRY
Outlet Connection TypeUNTHREADED FIRST OUTLET
Muffler DesignSTRAIGHT THROUGH
MaterialSTEEL LOCATION NOT OTHERWISE SPECIFIED
Outlet Outside Diameter1.500 INCHES NOMINAL FIRST OUTLET IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
5935-00-135-870853B INTERCHANGEABLE
Jack,telephone
Switchcraft Inc.
4310-00-147-389353B INTERCHANGEABLE
Unloader,magnetic
Curtiss-Wright Electro-Mechanical Corp Dba Steam & Air Solutions Div Curtiss-Wright Steam and Air Solutions
5940-00-171-0431 INTERCHANGEABLE
Terminal Board
5110-00-199-7287C24607 INTERCHANGEABLE
Reamer,hand
Kennametal Inc. Div Kennametal Industrial Products Group
3030-00-234-2247 INTERCHANGEABLE
Belts,v,matched Set
4730-00-288-9499 INTERCHANGEABLE
Tee,pipe to Tube
5940-00-309-01231385A INTERCHANGEABLE
Terminal Board
Birnbach Co Inc
5999-00-368-105321-255 INTERCHANGEABLE
Contact,electrical
Eaton Corp Opns & Technical Center
6240-00-583-960921-255 INTERCHANGEABLE
Lamp,incandescent
Precision Quincy Corp.
6760-01-168-808321255 INTERCHANGEABLE
Clutch Assembly,camera
Mekel Technology, Inc.
Cross-Reference Index
Part NumberManufacturer
FD78 PRIMARY Maremont Corp (USA)
MU723 Mahle Aftermarket Inc. Dba Ae Clevite Inc (USA)
763 Haviland Arnold Co (USA)
1030 PRIMARY Arvin Industries Inc (USA)
C1DD5230B Ford Motor Co Ford Parts and Service Div Government Part Sales (USA)
53B International Parts Corp Div of Midas-International Corp (USA)
666 Ap Parts Co Industrial Sales Div (USA)
C1DD5230C Ford Motor Co Ford Parts and Service Div Government Part Sales (USA)
416 PRIMARY Merit Industries Inc (USA)
21255 PRIMARY Walker Mfg Co (USA)
C1DD5230D Ford Motor Co Ford Parts and Service Div Government Part Sales (USA)
C1DD5230C Ford Motor Company (USA)
C1DD5230B Ford Motor Company (USA)
Related Parts
5935-00-135-8708INTERCHANGEABLE
JACK,TELEPHONE
53B
4310-00-147-3893INTERCHANGEABLE
UNLOADER,MAGNETIC
53B
5940-00-171-0431INTERCHANGEABLE
TERMINAL BOARD
5110-00-199-7287INTERCHANGEABLE
REAMER,HAND
C24607
3030-00-234-2247INTERCHANGEABLE
BELTS,V,MATCHED SET
4730-00-288-9499INTERCHANGEABLE
TEE,PIPE TO TUBE
5940-00-309-0123INTERCHANGEABLE
TERMINAL BOARD
1385A
5999-00-368-1053INTERCHANGEABLE
CONTACT,ELECTRICAL
21-255
6240-00-583-9609INTERCHANGEABLE
LAMP,INCANDESCENT
21-255
6760-01-168-8083INTERCHANGEABLE
CLUTCH ASSEMBLY,CAMERA
21255
5325-01-445-6442INTERCHANGEABLE
RING,RETAINING
212-55
5340-01-597-7162INTERCHANGEABLE
MOUNT,RESILIENT,UTILITY
21255

Frequently Asked Questions

What is NSN 2990-00-846-0732?

NSN 2990-00-846-0732 is a Muffler,exhaust, manufactured by Maremont Corp, classified under FSC 2990 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 2990-00-846-0732?

NSN 2990-00-846-0732 has 13 cross-referenced part numbers: FD78 (Maremont Corp), MU723 (Mahle Aftermarket Inc. Dba Ae Clevite Inc), 763 (Haviland Arnold Co), 1030 (Arvin Industries Inc), C1DD5230B (Ford Motor Co Ford Parts and Service Div Government Part Sales) and 8 more.

What NSN replaces 2990-00-846-0732?

There are 12 known substitutes for 2990-00-846-0732: 5935-00-135-8708, 4310-00-147-3893, 5940-00-171-0431 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of FD78?

Key specifications for FD78: Overall Diameter: 5.250 INCHES NOMINAL IN; Operating Position: HORIZONTAL; Inlet Outside Diameter: 1.875 INCHES NOMINAL SINGLE INLET IN; Inlet Location: OFFSET FROM CENTER IN BOTTOM. 19 total characteristics are documented in the Federal Logistics Information System.

Is NSN 2990-00-846-0732 still in active supply?

NSN 2990-00-846-0732 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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