Parking Lot Curb Stops

Hello, Been a long time since I have been here. I have been trying to find if the is a construction code regarding concrete curb stops. I had a contract to build 3 new parking lots. In the contract it spec'd 8 foot stops. I called my pre-cast supplier for a price when it bid. I did not know stops came in different lengths, I just asked for a price on concrete curb stops. The project is finished except for the stops. The supplier priced me 7 foot stops and can not get 8 foot ones. The old lot had 8 foot stops made back in the early 70's. That is what they want but after calling around to suppliers in 4 States all that I can find in 8 foot are made for Semi-trucks and are 1 foot tall. I can find a lot of stops in 6 & 7 foot but none in 8 foot, for a car. So my question is, is there a Construction Code for curb stops. I can not find one. Thanks