As per say, you're probably right, since the Vortec was when they went metric (7.4 liter = 454 cu in) and with fuel injection, but the block casting itself, I think has pretty much remained the same for a very long time, now.... Big Block Chevy
Anyway, they're very wide spread from the corvette to cars to trucks to motorhomes and boats as well.
Ford dropped it's big block 460 cu in V8 back in 1998, so there's no way that the present and smaller V10 has had such widespread use. That being said, the V10 is an excellent engine, but has to crank out more rpm's as a substitute for it's lack of cubes and once one gets used to the screaming, they should like this little engine (6.8 liter) very much so.
I've always wondered the same thing. With the 7.5 l. (460ci.) and 2 fewer cylinders to produce friction, the 6.8 should be working with a handicap. Ford never went back to producing the old 460, so they must have a lot of confidence in the V10. And a lot has to do with MPG and emissions. The V10 most likely gets some better MPGs than the cast iron 460. And from my reading, the V10 doesn't have the overheating problems the former was apt to acquire.
Now the late model GM Vortec is supposed to be all aluminum. At least the 4.8 and 5.3 l. are. And at least they share no common components with the previous Chevy small blocks built from around 1955 until 1999.