the only way to know is if your belt is too tight, it's quite obvious as the car tends to always have a drag brake and doesn't roll forward after letting off the throttle.

If that's the case, then simply buy a new front bulkhead, unfortunately Associated tried to gloss over this design flaw and didn't provide any recall, they simply kept the same part number. So long as you get a current bulkhead from a reputable distributor you will certainly get the newer version. If you buy the part from a LHS with old inventory sitting on the shelf for at least 6 months, then you might get the original version of the bulkhead:

http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_nkw=Associated+21312&_s op=15