that 318 made 477 at enginemasters with a 247/247 cam and the crosswinds intake on it. Had ported 2.02 magnum R/T heads on it.
Ran mid 11’s in my 3400 pound car with a smaller cam in it than it had at enginemasters. Flat hood all steel bench seat Duster with my 320 behind the wheel
Guy i race with has your 408 in his Duster, been testing/ racing it for 2 seasons, car is setup to race pretty well. Best has been 11.90’s at 110 thus far. Should run way better than that.