How Much Horsepower Required to Cruise Comfortably at 70 MPH?

i guess your right
RPM at MPH is a simple mathmetical equation based on transmission gearing, rear end gearing and tire circumference

but the 340 better have more power then the 318
so i still dont really get the question...unless hes just bragging hes getting a 340?
yeah, I don't understand the question. How much horsepower? a slant six missing a plug wire will still do 70 mph. We'll wait for more clarification on the question