Edelbrock 1406 accelerator pump

Cup size Maybe. The new ones have a removable cup. Old , the leather can expand and contract more and is permanetly attached
I agree, I like the leather better, ultimately, but it has one bad shortcoming over the newer rubber. It's not ethanol friendly. Ethanol dries the leather out terribly. Non ethanol gas didn't do that. But let them sit dry for any length of time after being submerged in ethanol gas and the leather cups are done for.