regarding the question of the 5.o liter V8 being identical to the Jaguar 5.0 V8,
I recall that the Jaguar design started out 3.9/4.4 liter V8 and had about 96mm bore spacing.
The design was drastically upgraded with the introduction of their 5.0 liter V8. They increased the bore spacing to 100mm just like the Ford Modular family.
However the Jaguar 5.0 has a slightly larger bore and a slightly shorter stroke and the design always had gas direct injection, I think from the top of the cylinder combustion chamber, not the side.
I think that they are not identical and I do not know if for an engineering mule, the Jag cylinder heads and direct injection would fit on a ford 5.0 liter block.
Regarding the 6.2 liter, there was a development 5.8 liter version that included cylinder deactivation for increased fuel economy, targeted for the Mustang. 102mm bore and 89mm stroke. Unfortunately, I actually heard that the cylinder deactivation system failed durability testing and this is why the development was stopped.
From what people at Ford said, the 6.2 family was designed for displacements from 5.5 liters to over 7 liters.
As you can see, ford jumped on the Ecoboost band wagon, making smaller size engines perform like larger engines with some degree of fuel economy savings, if driven conservatively. So they save gas in part throttle and are slightly more thursty at wide open throttle than a comprable V6 or V8. I guess, like someone already said, the Ecoboost is fords cylinder deactivation. Also, smaller engines weigh less.
7.8mm or .307" is getting down there as the distance between cylinder walls,(cylinder liners and water) but it seems to work, even for a truck. Daimler is down to 7mm or .27559" but utilizes an arch metal spray process that is propretary.
Once a major investment is made in an engine plant, there are always sacred cows that can't be changed. Thats why the creative guys at Ford Engine came up with the 5.0 liter, they maintained the use of the existing investment.