360 vs 383

Plus a 383 especially rebuilt with an overbore is close enough to 408 size (torque)(lower rpm power), spend the stroker money on the top end instead.
These are just the "quick and easy" kits available and most commonly used. What it shows is that the 23 cubes difference can end up being 88 cubes difference in a click of a button and about 500 more bucks. There are some wild and crazy builders that do more cubes than these kits, but for the 99.8%, these are the kits used.