R380 INPUT SHAFT SEAL

I've got my engine out for replacement and i'm doing the clutch and rear main whilst it's in bits. I've hit a snag else where that requires another parts order, but thought I might as well replace the input shaft seal behind the plate in the bellhousing. Ive checked my parts microfiche and it doesn't list the part i require. Can anyone help with the correct part number please?

ftc5303,though if old isnt leaking

it's wet inside the bell housing. you don't advise changing whilst it's out?

if its leaking you are better too,if its not why take a risk