Carroll,
I'm saying it has much greater potential than the 4" bore combination when used for a max effort engine. This type of motor is common in offroad truck unlimited class and dirt Late Models where every combination of bore, stroke, rod length, compression, etc. has been tried in an effort to produce max power WITH drivability. The 4.155 bore (or close to it) has become standard. You won't find a 4" bore combination in these classes. One reason is the 4" bore, with any stroke, won't produce the power required to be competitive at that level.
From a reliability stand point, the shorter stroke has lower piston speed and therefore less tension loading of the rods and piston pins. Lower piston speed also produces less friction and better top end power. Lower piston speed produces better cylinder fill at high rpms.
The larger bore allows better cylinder fill through decreased valve shrouding. It also allows larger valves.
The design is intended for racing but will also work for "excessive street overkill" if you need that big of a motor or if you just want a 427 small block. If that's the case, I wouldn't build a Windsor with over a 4" stroke.
You haven't heard about the Dart specifically, because it's new for Fords. You haven't heard about this TYPE of motor, IMO, because the Windsor, with its relative ease and inexpense of stroking, has sufficed for the street.
Does anyone remember, the PAW catalog, in 1985, offered the "Super Gorilla aluminum 427" small block Chevy. I remember it as being the first time a dirt Late Model engine combination was offered to the Hot Rodding community. I can't tell you how badly I wanted one of those then and I new exactly what kind of car I'd put it in too.
Scott