That's the risk.
Changes in fuel composition in the early 70s killed some rubber parts. And that happened again a few times after that as Im sure you know.
There are some guys who rebuild fuel pumps, have parts, and/or will uncrimp and recrimp the crimped types.
Mancini had rebuild kits for the after market carters. Not sure if they still do. Watch out for the spring force. Its too high on some of the Carters. Should max out around 6 psi, not 7 or over.