This thing is an absolute beast, and it's currently setup underdriven! Built back around 1990 and put into garage storage in '95. I bought the car from an acquaintance for my kids, so obviously this has to go. No idea about the internal specs, but it was done right by the mechanic owner back in the day -- 4-bolt 350 block, 400 crank, double-hump heads!
I rebuilt both carbs (and Cerakoted them black), new plugs, oil & filter (twice now), cap & rotor (HEI with an MSD box), coolant, scoop, etc.. $4500 for the complete engine and blower (including the custom-made flywheel), $4800 with the Saginaw transmission (nothing special, but it works and it was the surviving transmission back when the car was put away -- this thing was even eating Muncie rock-crushers with 4.10 gears and small tires with the pulleys swapped to overdrive the blower) or $4900 with the headers (Patriot long-tube headers in a G-body 1-5/8" to 3", ceramic coated $700 new), $5100 with both.
I'm sure it would benefit from having the carbs properly tuned, but it still starts and runs great! I've had it up and down the road a couple of times, and it boogies!! I'd guess it's around 500-520HP at the wheels right now with the potential to be 600HP+ by swapping the pulleys. Email for a video of it running and revving.