Not sure what part number Carter you currently have but Mancini Racing sells a rebuild kit for M6902 and M6903 Carter pumps; $44.95. Maybe a good interim option.
unfortunatly mine is the non rebuildable type, otherwise i would consider it...not sure what part number mine is as its a very old one (atleast 22 years) but i can tell by looking at the outside since the diaphram is crimped on
