Go to http://www.idpa.com and ask them to be safe. If they give you an answer in the affirmative make a copy of the E-mail to take with you to the matches if you want to eliminate any hassles from anyone.
I know that in ESP or CDP you can use aftermarket rods as long as they aren't tungsten or some other heavy weighted material. In my rule book it doesn't specifically mention it under the SSP division....