Here was my thought process on v6 vs. v8. It wasnt the cylinders, but the horsepower. The v6 has over 300 horse, and thats at least what the 60's Z28 had if I remember correctly.
At the pump it will take regular, get better gas mileage, and probably be less to insure. What adjustment I will make, is to the exhaust note. After that I will be plenty fast, and sounding good