Totally different applications. At that level of compression, 3-4% per point is normal (apples to apples displacement). In reality, the 440 has a big bump on power (0-5250 RPM) already on the 383 out of the gate if everything else is equal, so that's not really a good comparison.

383 will peak likely around 5,750 - 6,000 RPM.
440 will peak likely around 5,000 - 5,250 RPM.

At the end of the day, regardless, Torque x RPM / 5252 = HP. Where do you want your power curve?

383 would need more gearing and a higher stall, but HP is HP. On the street, you would - if I dare say it - be better off with LESS torque at low speed. Low speed torque is fun though, so it's a trade-off. Less likely to have problems with an engine that peaks well below 5,500 than one that needs to wind out to 6,250 - 6,500 to make power.

Also, 440 source heads - they are essentially an aluminum OE replacement. Yes, they flow marginally better OOTB (20-ish HP) but really, same cam in both, the 440 will make much more power over a 383 from 0 - 5,500 RPM.

Even after the 440's HP peak, it will still take some RPM (time) for the 383 to make up the 50-60 ft/lb deficit it has against the 440.

So, my vote - 440. Don't worry about the compression, Stealth heads - Performer RPM intake manifold - .530 to .550" lift / 230-235* duration / 110-112 LSA Hydraulic Roller. 3.55 - 3.73 gear. 3,200 - 3,800 RPM converter. Great street car with plenty of power.


1969 Plymouth Road Runner (440 w/ Boost! RIP) now a low-deck 470 with hotchkis suspension, nascar boom tube exhaust, & big brakes.