USRA rules have an 8000 rev chip. Otherwise they are pretty much a USMTS car.

As Bill said, UMP cars have soft Hoosier tires. Most USRA tracks run the American Racer KK704 tire. It needs to be ground or sanded after every race to keep the grip in it. If you are use to the soft Hoosier, it is a big change to the KK704. The harder tire is suppose to help keep $$ down by not being able to hook up a high dollar high horsepower engine. The suspension sophistication on these cars now though still allow a lot of that power to be put down. Definitely need to have the setup right though to get there.