My motor was only 385 ci (4.040X3.75). The key to making power in a stroked 350 is putting a long rod in it. I ran a 6" h-beam (the pin was up into the oil ring land). I had a huge solid roller cam and ported Victor Jr heads that were angle milled (made it a 20° motor, not typical 23°). It was an honest 600 how, not "yeah, I got a 600 hp SBC". It was internally balanced, so no damper or flex plate weights, and because of that, it ran smooth all the way to 8k (I had the light set at 7600, and an 8200 pill in the box). That kind of RPM is only possible with a long rod because piston speed becomes a serious issue at those bore/stroke/RPM's. It also involves a lot of clearancing the bottom end. With JE forged flat tops, it was at 11.1 to 1 after I cut the valve reliefs in the pistons if memory serves correct. I also had a Cheater plate on it, but bought Power shot solenoid covers (they barely fit, but they did), another street racers secret. I ran a separate fuel cell up front for the nitrous with 110 octane to keep it from detonating.
I told everyone at the street races it was a 355 with a solid cam and a Power shot wide open (Power shots were 125hp, Cheater's we're good for 250). All of this was in a 71 El Camino. I boxed the rear control arms, put a sway bar in the back, deleted the front sway bar G body 6 cyl spring (they store more energy to unload better), and had 28x11.50 ET Streets on the back. The convertor was a 3800rpm stall, with a 4.10 geared 10bolt with good parts to make it live, with a TH350 (400's Rob to much power). At LACR (R.I.P), it ran 12.0's, shutting it down at 1000ft (no cage), and I always squeezed it on the last pass of the night (10.90's). When I squeezed it, it would pull both wheels for about 30ft, and carry the left front for about 100ft. I could drive it the 70 miles there and back too. But I always put the "NT", since it was a purpose built street racer. Shit, I even still had a clutch fan (drilled and drained), and a column shift.
Man, I miss those days.