As one of my buddies, a former NY street racer, would say: "that stock air cleaner ain't foolin' nobody!"
As for the time, I find that - in spite of being arguably a naturally-impatient person - I'm happier with projects I take my time with rather than being in a hurry.
Its ok to take your time when your building a cool machine like that. Its better to take your time and be sure you get it right rather then rushing and maybe missing something. It looks good so far so keep up the good work. I run them same valve covers and I have been happy with them. Ron