Working with an original 1948 Chevrolet 3600, 216.

While looking for a distributor cap I was asked if it were the tall or short type.
What would’ve been original to the 1948? What are the height differences between the two? The one currently on it is roughly 2 inches tall not counting where the plug wires attach. In just several hundred miles the cap wore out where the rotor button contacts the very center coil input.