I helped run a 451 on the dyno today. This is a street engine with Trick Flow 240 heads, Performer RPM intake, MSD ready to run distributor and a 230/230 hyd roller camshaft. We ran it with 1 7/8 step headers. Engine made 520 hp and 550 torque. Not a race engine but it still has enough power to push a car down the track just fine. It is mellow enough to daily drive but it makes more power than any muscle car ever had so it won't be a slouch on the street. Video of the console during the testing: https://youtu.be/1ORVnCnCizI