I checked the 2 thin black halves that go around the knurled journal "the rear main seal" & the halves fit flush in the block/#5 main cap on my 360 but one half was too big for a 318 #5 main cap that I tried it in (I have no 340 stuff) so the other half would for sure be the same & be too big to fit in the block recess. "The rear pan seal" that sets in the wide shallow groove in the #5 main cap to seal the main cap to the pan, set in there fairly flush on my 360 #5 main cap but the 318 cap I have has a flat wide surface as opposed to the wide shallow groove that my 360 caps have so I could make a comparison. here are some pics. I'm thinking the 340 might be the same here as the 318. EDIT these above are a 360 cap & I will see if I can get some better pics out of this complicated Samsung camera (at least it ain't caught on fire).