The cap has a vent on it for a reason.. to filter out any dirt.
You can peel of the sticker, add green food dye, run heatshrink over hoses, etc.. many ways to skin a cat.
So to use a non filtered cap.. keep an eye on the filter a lot more.
Goes the same as pouring alcohol in without using a screen to pickup debris.
You can buy the original caps from GM, and Advance also sells them in their "Help" section.. just dont put the 20 years old cap on the tank.
HTH