Well there is it, flat-plane 5.5L engine in the C8.R.
Liveries different for the 3 and 4 next season as well
https://sportscar365.com/imsa/iwsc/c...ils-confirmed/
From S365:
The engine, producing 500 horsepower and 480 foot-pounds of torque, limited per GTE regulations, has been paired with a new compact Xtrac six-speed sequential gearbox that was developed specifically to provide room for a race-specific diffuser.
Louth said the biggest gains with the mid-engine layout has been with an improved weight distribution and aerodynamics