Notice I said 'one of these engines'. I used to port heads and build drag cars for a living. No blown, just normal aspirated and some nitrous. Have been crew on 720+ inch fat block Chevy that ran sevens @200+. 1200+ HP with 3 stage nitrous. Got to play with 450 inch SBC, 460 and Boss 302 Ford, 440 and true 426 Hemi. American Motors (AMC49!) 395 inch motors that ran in the high nines @ 140. 700 HP is simply not true, don't flog it, somebody's sadly mistaken. In my experience, most people have a heart attack if taken on a ride in a ten second car.
My younger brother had a beat up '68 AMX that we did the street racing with. Car Had Isky hydro cam with only .010" more lift than stock, well used 406" motor from an Oklahoma State Patrol car. We lucked out, it had a good rebore job with forged pistons (8.5/1 compression!)in it. Car would run all day long 12.00-12.20s, motor making maybe true 375 horse if we were lucky. We could re-motor in one evening up to 12.5/1, 324 degree .640" lift cam. Still single 4 BBL. That engine could bust off 10.60-.70s @ 130 mph through the mufflers but with small drag slicks. Drove it around on the street like that, full bodied car, weight 3250. Didn't need dyno to lie, just pull it up to the line and reality takes over.............you have no idea how embarrassing it can be for one of the big three to get beat by a RAMBLER, and most of those other engines were quite a bit bigger than ours.
The 700 Hp numbers based on this real world car. AMC Hornet pro stocker, 368 inch motor, dynoed 739 HP @ 9000 rpm. Ran 8.70s @ 150-155 mph, back in '74. I got to tear down engine and expose all her secrets.