I have owned a 73,72 and 69 Newport 72 and 73 had 400 2 barrel and 69 had 383 4 barrel the 73 newport had 140,000 mi when I got the and it was one of the fastest cars i have ever driven it had 273 rear end just like the other and a 69 383 4 barrel with high performance intake carb and 3 inch dual l exhaust would loose to my 73 in any kind of race would anyone know why 73 400 would be that powerful?