For N/A motors, 2.1 is about ideal (my opinion)... you can take it out to a perfectly square bore/stroke, and with custom pistons you can have a non interference setup.
The M44 crank provides a marginally longer stroke, and to my knowledge, it's cast, rather than forged...
My target was around 100hp per liter, without being too fussy and reasonable for normal, high-traffic NYC driving... hopefully I can get the car on a dyno in october and we'll know how close I got.