The 700CI is more common I think to IHRA and the 500 CI are in NHRA.Remember the part of the article that talks about rental engines.Fact is Jegs has started a program for that.I would think it is a way to get back some of that R&D money.All true about the secrets in the builds of these engines.When rented,the guy from the rental program is the only one that touches that engine and tunes it and it is taken back after the race is over.