Ok for some more little engine insperation let's see what changes with engine size bore and stroke.
First lets use parts common to all engines and use desktop dyno to see what goes on.
The parts will be pocket ported heads, small tube headers and a Extreme energy 256h cam, Quadrajet and dual plane manifold, and pretty average sized valves of 1.84 inlet and 1.5 exhaust
Chev 262 324 hp@6000 rpm, 324 ft-lbs @4500 rpm
Chev 265 326 hp@6000 rpm, 327 ft-lbs @4500 rpm
Chev 267 320 hp@6000 rpm, 327 ft-lbs @4500 rpm
Chev 283 331 hp@5500 rpm, 343 ft-lbs @4500 rpm
Chev 302 336 hp@5500 rpm, 360 ft-lbs @4500 rpm
Chev 305 330 hp@5500 rpm, 362 ft-lbs @3500 rpm
Chev 307 333 hp@5500 rpm, 364 ft-lbs @3500 rpm
Chev 327 334 hp@5000 rpm, 384 ft-lbs @3500 rpm
Chev 335 330 hp@5000 rpm, 390 ft-lbs @3500 rpm
Chev 350 334 hp@5000 rpm, 406 ft-lbs @3000 rpm
Chev 383 331 hp@4500 rpm, 442 ft-lbs @2500 rpm
Chev 400 331 hp@4500 rpm, 463 ft-lbs @2500 rpm
Ok so you can see that you need heaps more timing on the camshaft to get a bigger engine get moving at anything more than higway revs and also that even with pocket ported heads the heads and valves are the limit not the size of the engine, after 5000 rpm the 302 (probably the best Chev small block) has got all the numbers over the 400 and at 6000 rpm a 302 is making 287 ft-lbs of torque and a 400 has long since spent all his grunt is only making 225 ft-lbs, 400 drivers watch the small engine at the finish line and watch him while your getting wheelspin off the start line too : )