Great info. So modern brakes are a must.When ERA built my first GT40 had 15" wheels that limits the size of the brakes. The brakes were not power assisted and the engine was down in power (330ci). I ran at Road America and the Mustangs were faster and could go deep in the turns.
My second ERA the engine was a 409 with 17" wheel with bigger power assisted brakes. Race rubber etc. The car was a total different car and could run with modern cars at Poconos racetrack.