Honestly, this is something that you should go to your Solo Events director about. For a modification this small, with such a minor effect, and at a regional level, I HIGHLY doubt that your Solo authority would snatch you out of class for it. It's one of those things where people don't really start to care that much until you are in a serious contest for a trophy in a class populated by very competitive people. Even then, I doubt that anyone would care, and only a bitter and narrowly beaten competitor would demand any action on it. Mine said he wouldn't care if I got a lightweight battery (shave 25lbs right off the top of my front-left corner!)
Now if you were hitting up the Divisional, National, or Pro Solo tours then they would care. At Nationals they are really stingy. I know of one guy who actually got eliminated from a 1st place National trohpy becaue the cat on his Honda was 6" back from where it should be...
Until you're there, don't worry about it but to be on the safe side, as I said, talk to your Solo II board member and get their approval.
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...