70 nova's never had a 454 in them and the horsepower rating would have to be assessed from the year the engine is and if anything has been done to the engine other than being stock.
The 1978 Chevy 454 has a 240 horsepower and 360 foot-lbs. of torque. Many enthusiasts have built 454's that produce power outputs approaching 600 horsepower or more.
how much horsepower does a 6.0 vortech motor have
1970
210 hp
the 454 out of the chevelle in 73 had 265 horse.
Carefuly
280hp
Advertised Horsepower is---245HP @ 4000 RPMs.
Around 290hp
230 HP
A 1995 454 engine normally found in Chevy Suburban's produced exactly 230 horsepower and 385ft-lbs torque in stock form.
It's done all the time, If you have the KNOW HOW.