The bore to stroke ratio and the rod ratio for the 400 are pretty close to optimal for making great HP per cube. What the 400 lacked was any sort of decent compression and quench. So with modern cylinder heads and valvetrain it should produce higher HP/Cube than a longer stroke variant all else being equal.I'm pretty sure the de-stroked 5.5L LS variant they use in the new Z06 Corvtte has a very similar bore to stroke ratio as the 400.

So for the same head flow a 400 will rev higher with less side loading than a 440 due to the lower relative piston speed at any given RPM

I wish I had bought that offset ground 383 crank AndyF had a while back, it was like 3.52" stroke with 2.200" rod journals. and a 6.8" rod would be a great high revving combo at ~423 cubes.

It's just more cost effective to build a small block these days for the same relative HP output.

I do enjoy Joes videos!