SS/B Barracuda project

Valve Cover Breather Cap
I found this Oil Cap the other day on a forum here in Sweden. I figure Chrysler did not make these caps specially for the SS Cars, but rather looked for something already on some manufactures shelf. I have seen similar caps on Fords from the fifties or maybe earlier. And it wouldn´t surprise me one bit if this cap is form an old Flathead... :)
Only reason I can think of for using a big cap like this, is a bigger cap will breath better... I may reveal my ignorance here, but till someone tell the real reason for not using a ordinary cap, I´ll got with this theory.
Is the Cap I have found, of the same type used on the Race Hemi when delivered from Hurst?
Cap is 3 by 2". Other picture is from Judy Lilly´s Barracuda.
Comment on, don´t be shy and take a look at my earlier post about the Battery Support Plate. Someone should know something about this. I think this Forum still have something to proof, I mean I have have many posts, still left with a question mark behind.
Thank You

20170109_170709[1] myOilCap.jpg
20170109_170208[1]JudyOilCap.jpg