I was just reading the latest issue of "Hot Rod" (yeah, I still like that rag, been reading it since I was a kid).
Anyway, they noted that typical 'well built' modified modern engines put out about 1.4 horse power per cubic inch, on average. Considering that for MANY MANY years 1 horse power per cubic inch was sort of a holy grail thing we've sure come a long way!
You can get 400 horse (flywheel) from a 302 running STOCK pistons and lower end components by simply bolting on readily available cost effective modern parts. Heads, intake, cam, EFI components etc. NO power adder needed, THAT is quite impressive. Want to get wild? Yeah I can see 500 plus out of a stroked and mild bore 302. Not that common, but 'can do'!
Assuming a typical 'build up' for a 302 brings it to 347 cubes X 1.4 = 485 horse. The KEY is knowing what parts work together well, it's the total PACKAGE that determines the final output. Mess with the recipe, even just a little, and you could LOOSE (or GAIN) a lot. Tricky stuff getting it right.
Sounds like Orlando Mustang has the recipe 'dialed in'.