Like I mentioned the part (fuel filter) should or could be the same as older 7M's not sure if the part number changed I tried to find that spare fuel filter on the shelf, see if there was a number on it, but I've cleaned up quite a bit in the garage and not sure where I put it LOL! Here somewhere. I did find the same part number, shows 6 elements in a February 1952 reprint parts catalog for 3T's,(3T1 & up not, 3T's were built til 1955) Form 12043. I thought there was 4 elements in that housing, possibly that is a good parts number or one you can cross reference.
Don't quote me, as I have a correction for the oil filter elements. As I recall after looking, there were apparently 2 types, a bypass type and full flow type filter housing, the book referenced above shows this and is titled "Parts Catalog Insert" so it was likely an upgrade followed by a bulletin. I recall that earlier tractors had an oil cooler, one of mine does, the other has the lines but the oil cooler is missing. The lines circulate the oil to the cooler, if it were to plug, the bypass would allow oil to circulate, hence that type of filter housing. I believe,(and I am not sure at what tractor number) these oil coolers were omitted, deemed unnecessary and the subsequent full flow filter housing was used. That's the thing, you have to have the correct books for your serial number tractor to start, read carefully and make sure you have the right component. Being so old, its hard to say if dealers still reference the old numbers, cross em over and or still have mircro fiche info on them. The dealer near me services a lot of older tractors, as lots of towns still have them but not as old as these, not sure where to source these filters and what part numbers are good still. I recall Foley CAT in Kansas was really good on old parts numbers, someone in particular there was good at sourcing things for these older tractors.
3T1 to 3T7120 = 4A332 element, 2 required (Bypass Type)
Effective with 3T15942 = 9F 6700 element/disposable (Full Flow Type) 2 required
I looked back in that military tech manual, numbers seem to be different, easiest way to deal with this is to get the correct books for your tractor, parts catalog especially. Serial number is on the left side rear engine block and left side above the final drive housing on the back side of the bevel gear housing, tags, if tags are missing, its stamped directly under the tag.
Your 3T, being an oil clutch model, either a late model factory built say early 50's or an older one that was retrofit with the field kit to convert over to oil type, the parts catalog for 3T's (parts catalog for serial numbers 19,999? and above would be correct for your tractor) There are 2 books, one stops at around 19,999 (?), the other covers 19999 (?) to 28,056 (?) or approximately (28,000+ was end of production of the 3T) The latest Serviceman's Reference Book for 3T's I have and includes 7M's is FORM FEO31237-00, which shows both type of clutch and lists no serial number, which means it should have been inclusive of all 3T's as it was likely printed well after that production model was completed. You need a parts catalog that covers the entire run or the 2nd one I mentioned above 19,999, D7 books are always on ebay, nice used originals, and or well used, you can source them from CAT legendary literature too.
Hopefully this may help.
