372or 416 and why

All the science thinking, engine dynamics and the pro's and con's aside, the engine size you want is something you'll have to want.

The bottom line is no matter what, it is what you want. Nothing beats cubic inchs period. How well it works for you or what you need it for and how it will be used is another story.

Some people will point to a 408 and site it poorly for it's side wall loading, crummy ratio's vs. a shorter stroke engine.
Then theres the other veiw of just simply having lots-o-cubes for lots-o-torque on demand.

The 360 crank into a 340 block is a very old stroker combo that performs very well and makes very good power that doesn't need any real extra parts tricked out to balance out or max out it's abilty or be curtailed by it.

The 408, will have to have head work done on most any head you have for it due to it's sheer size. It will need alot of port volume to operate well or you will probably curtail the engines performance in RPM and power output. That is easy to do on a stroked small block of this size.

The 372 can use less head and work to the head while still having the abilty to make excellent power. An excellent matching head for a 372 is stock or lightly preped Edelbrock heads or 340/360 heads with some work done to them. Probably in the area not exceeding a good valve job, light bowl work, ending with a gasket match.

(Of course this is a projection based on probablity, actual work needed will be a combo dependent thing and intended useage of the car is another item to the list of which all things must be decided on, worked with and adjusted on.)

In the end, it will be what you really want to do.