NSN = National Stock Number - this is the military's part number
TM = Technical Manual (these contain troubleshooting, repair and parts information)
Download TMs here:
https://www.logsa.army.mil/etms/index.cfm, search for H-140 in the title
Find NSN (or manufacture's part number if it's there)
Then cross NSN to other parts numbers --> I like to use
www.wbparts.com
Then go to your FLAPS = Favorite Local Area Parts Store to buy part.
Your part number for the filter is R20P --> crosses to NAPA 3614
The base number is RK22350-02 --> it doesn't cross to much else --> it shows up all over the internet
And the entire fuel filter assembly is 230R --> it doesn't cross to much either bit it's all over the internet for purchase.
View attachment 71_200 Series.pdf
Above is the manufacture's series of part numbers (Parker --> and they match the TMs)
Hope that helps. Good luck,
Al Jones
TWO H-140 heaters...