Catch tank

[dazzler]

As a few of you know, I have an ALT engined 5.5.
And after lots of looking/reading/pestering members I know I cant do anything to improve performance.
So im looking to improve elsewhere. As I know nothing about ICE I thought i'd start with dressing the engine.

So looking around for ideas, ( polished engine cover, oil cap and dip stick), I came across a catch tank on ebay item no 230933996557 (dont know how to put a link up),
Just wanna know will it do any harm? and yes i know its pointless, but it is cheap...