Just to add more what-ifs....
I did a quick computer simulation using the Dynomation5 protools sim. using a very mild near stock 440 specs (with manifolds) and a theoretical 284/0.484 cam with 108 LSA installed at 108.
Peak Power was 412@5500 RPM, and torque was 494@3500 RPM.

Then I just widened the LSA to 110, and slightly shortened the intake duration, same lift and install position and got:
Power 416@5000 RPM, and 509 ft/lbs @ 3,000 RPM.

The interesting part is the difference in low end torque:
RPM 284 cam 275 cam Difference
1000 248 278 +30
1500 366 390 +24
2000 445 463 +18
2500 480 498 +18
3000 493 509 +16
3500 494 507 +13

I know it's just a lame simulation, but I am trying to show how the power curves differ, and how the newer cams are tring to get the same or better peak power while enhancing the low end power. This dosent even address the differences in ramp rates and the greater lifts the new cams have. On the other hand the newer style cams are harder on the valve train.

Then I made one change to the sim models, added headers with open exhaust.
Peak HP = 478@5500, TQ = 541@4000 (284 cam)
Peak HP = 476@5500, TQ = 552@3500 (275 cam)
The samller cams torque advantage was still there, just not as big a difference, and with the better exhaust the 284 cam made slightly more peak power.