Yea but they didn’t. That’s the point of the question. The “high horsepower” 440 was still an 8:1 comp engine (likely closer to 7-1/2:1 with pistons .150 down) with all of the same hard parts as the “low horsepower” model. They definitely didn’t “tune” 65 horsepower in to it. From the article posted above;
“With the exception of a full-size Chrysler, the 440 was unavailable for public use, and even then, the civilian version was rated for 195 hp. Those destined for police cars were instead rated for 255 hp and 355-lb.ft. of torque. The extra power was enhanced by dual catalytic converters fitted to a true dual exhaust system and electronic spark advance (except in California) and supported by heavy-duty parts like a shot-peened nodular cast-iron crankshaft, double-roller timing chain drive, moly-filled top compression piston rings, high-load valve springs with dampers, a windage tray, chromed and hardened exhaust valves. “
So dual exhaust with dual cats and “electronic spark advance” was worth 65hp? Not a chance.