Should I buy this 440?

TT5.9mag said
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.

According to "Chrysler Engines: 1922-1998" by Willem Weertman, the E85-code police HP engines went through 1975 and had true duals, low-restriction air cleaner, and the Magnum/Super Commando camshaft. If the HP 440 was continued through 1978 like the Hemmings article says (seen it referenced as code E86) I'd bet it also came with the bigger cam which would make up for at least half of that 65hp difference. The 1972 440 HP in the "civilian" cars was rated at 280hp net without catalytic converters which isn't that far off from 255.

Regardless $400 is a good deal for a 440 of any kind in running shape, I'd take it. @AndyF says in his BBM book that cast cranks are good to around 500 HP, forged to about 600.

Also from personal experience, my cousin had a 1972 Polara with a non-HP 440. It originally had single exhaust at most 2-1/4" diameter and when we put 2.5" duals on it it picked up a TON of power, at least 30 HP based on my early-20s butt dyno lol.