Zerkfitting
Team Owner
It looks like there are talks about an international spec for prototypes. A common chassis that can handle different engines and body work.
http://www.racer.com/imsa/item/102968-imsa-talks-continue-on-2017-spec-prototype-chassis
http://www.racer.com/imsa/item/102968-imsa-talks-continue-on-2017-spec-prototype-chassis