I ran a car in P/SA at an NHRA Divisional race last year with an expired set of belts. I was told that they did not even look at them if they were not needed for the class. If I were running a slow car on a consistent basis I would definately have a set.
I have a set of RJS camlock belts that I took out this past weekend. Expiration date 5/12. Send me an email if you are interested. I will give you a good deal on them.
aarontallison@gmail.com