Not sure on the rev limiter question, but I don't know if those needles are real accurate. There is a way to get your odometer to display digital rpms. I will find the instructions. There was an old thread a few months ago too. Every once in a while, this question comes up.
I made two changes to the front of my car. One was to delete the stock grill and the other was to add a chin spoiler. There are lots of places that sell these. The grill deletes run $45 - $90 and the chin spoilers are $60 - $90 from I can remember.
www.mustangtuning.com is where I got mine...they had the best prices that I could find and include shipping. This is essentially what the front-end of a Mach 1 looks like minus the shaker-hood of course.
I keep my stock parts in case I need to sell the car and make it original. I have a friend with an '03 Vette. Believe it or not, the rear window (which was classic only to '03) was considered ugly by many back then. Many guys put in the '04 windows in their '03's and the cars have lost much value now unless you find an original '03 window. My stang will probably NEVER be that vintage, but I always remember that example and therefore keep my stock parts.